errors faced on worpress version 5.8.2

[zainabsaeed]

errors are as follows:

displayed inside wordpress admin dashboard:
/wp-content/plugins/catchtheweb-barclay-epdq-payment-gateway/classes/includes/settings-barclay.php on line number 5 and 6

displayed on the webpage's checkout page:
/wp-includes/functions.php on line 5663

I am using Astra WooCommerce theme FYI.

errors actually:

when I visit woocommerce>payments>barclay ePDQ, it shows following error inside wordpress admin dashboard when changes are saved:

Notice: Constant AMERICAN_EXPRESS already defined in /home/abc123/public_html/mysite.com/wp-content/plugins/catchtheweb-barclay-epdq-payment-gateway/classes/includes/settings-barclay.php on line 5

Notice: Constant SELECT_PAYMENT_METHODS already defined in /home/abc123/public_html/mysite.com/wp-content/plugins/catchtheweb-barclay-epdq-payment-gateway/classes/includes/settings-barclay.php on line 6

I get the following errors on the website's checkout page:

Thank you for your order, please click the button below to pay with Barclay ePDQ.

Notice: id was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), include('/themes/astra/page.php'), astra_content_page_loop, do_action('astra_content_page_loop'), WP_Hook->do_action, WP_Hook->apply_filters, Astra_Loop->loop_markup_page, Astra_Loop->loop_markup, do_action('astra_page_template_parts_content'), WP_Hook->do_action, WP_Hook->apply_filters, Astra_Loop->template_parts_page, get_template_part, locate_template, load_template, require('/themes/astra/template-parts/content-page.php'), the_content, apply_filters('the_content'), WP_Hook->apply_filters, do_shortcode, preg_replace_callback, do_shortcode_tag, WC_Shortcodes::checkout, WC_Shortcodes::shortcode_wrapper, WC_Shortcode_Checkout::output, WC_Shortcode_Checkout::order_pay, wc_get_template, include('/plugins/woocommerce/templates/checkout/order-receipt.php'), do_action('woocommerce_receipt_barclay'), WP_Hook->do_action, WP_Hook->appl in /home/abc123/public_html/mysite.com/wp-includes/functions.php on line 5663

Notice: order_total was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), include('/themes/astra/page.php'), astra_content_page_loop, do_action('astra_content_page_loop'), WP_Hook->do_action, WP_Hook->apply_filters, Astra_Loop->loop_markup_page, Astra_Loop->loop_markup, do_action('astra_page_template_parts_content'), WP_Hook->do_action, WP_Hook->apply_filters, Astra_Loop->template_parts_page, get_template_part, locate_template, load_template, require('/themes/astra/template-parts/content-page.php'), the_content, apply_filters('the_content'), WP_Hook->apply_filters, do_shortcode, preg_replace_callback, do_shortcode_tag, WC_Shortcodes::checkout, WC_Shortcodes::shortcode_wrapper, WC_Shortcode_Checkout::output, WC_Shortcode_Checkout::order_pay, wc_get_template, include('/plugins/woocommerce/templates/checkout/order-receipt.php'), do_action('woocommerce_receipt_barclay'), WP_Hook->do_action, WP_H in /home/abc123/public_html/mysite.com/wp-includes/functions.php on line 5663

Notice: billing_first_name was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), include('/themes/astra/page.php'), astra_content_page_loop, do_action('astra_content_page_loop'), WP_Hook->do_action, WP_Hook->apply_filters, Astra_Loop->loop_markup_page, Astra_Loop->loop_markup, do_action('astra_page_template_parts_content'), WP_Hook->do_action, WP_Hook->apply_filters, Astra_Loop->template_parts_page, get_template_part, locate_template, load_template, require('/themes/astra/template-parts/content-page.php'), the_content, apply_filters('the_content'), WP_Hook->apply_filters, do_shortcode, preg_replace_callback, do_shortcode_tag, WC_Shortcodes::checkout, WC_Shortcodes::shortcode_wrapper, WC_Shortcode_Checkout::output, WC_Shortcode_Checkout::order_pay, wc_get_template, include('/plugins/woocommerce/templates/checkout/order-receipt.php'), do_action('woocommerce_receipt_barclay'), WP_Hook->do_actio in /home/abc123/public_html/mysite.com/wp-includes/functions.php on line 5663

Notice: billing_last_name was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), include('/themes/astra/page.php'), astra_content_page_loop, do_action('astra_content_page_loop'), WP_Hook->do_action, WP_Hook->apply_filters, Astra_Loop->loop_markup_page, Astra_Loop->loop_markup, do_action('astra_page_template_parts_content'), WP_Hook->do_action, WP_Hook->apply_filters, Astra_Loop->template_parts_page, get_template_part, locate_template, load_template, require('/themes/astra/template-parts/content-page.php'), the_content, apply_filters('the_content'), WP_Hook->apply_filters, do_shortcode, preg_replace_callback, do_shortcode_tag, WC_Shortcodes::checkout, WC_Shortcodes::shortcode_wrapper, WC_Shortcode_Checkout::output, WC_Shortcode_Checkout::order_pay, wc_get_template, include('/plugins/woocommerce/templates/checkout/order-receipt.php'), do_action('woocommerce_receipt_barclay'), WP_Hook->do_action in /home/abc123/public_html/mysite.com/wp-includes/functions.php on line 5663

Notice: billing_email was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), include('/themes/astra/page.php'), astra_content_page_loop, do_action('astra_content_page_loop'), WP_Hook->do_action, WP_Hook->apply_filters, Astra_Loop->loop_markup_page, Astra_Loop->loop_markup, do_action('astra_page_template_parts_content'), WP_Hook->do_action, WP_Hook->apply_filters, Astra_Loop->template_parts_page, get_template_part, locate_template, load_template, require('/themes/astra/template-parts/content-page.php'), the_content, apply_filters('the_content'), WP_Hook->apply_filters, do_shortcode, preg_replace_callback, do_shortcode_tag, WC_Shortcodes::checkout, WC_Shortcodes::shortcode_wrapper, WC_Shortcode_Checkout::output, WC_Shortcode_Checkout::order_pay, wc_get_template, include('/plugins/woocommerce/templates/checkout/order-receipt.php'), do_action('woocommerce_receipt_barclay'), WP_Hook->do_action, WP in /home/abc123/public_html/mysite.com/wp-includes/functions.php on line 5663

Notice: billing_postcode was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), include('/themes/astra/page.php'), astra_content_page_loop, do_action('astra_content_page_loop'), WP_Hook->do_action, WP_Hook->apply_filters, Astra_Loop->loop_markup_page, Astra_Loop->loop_markup, do_action('astra_page_template_parts_content'), WP_Hook->do_action, WP_Hook->apply_filters, Astra_Loop->template_parts_page, get_template_part, locate_template, load_template, require('/themes/astra/template-parts/content-page.php'), the_content, apply_filters('the_content'), WP_Hook->apply_filters, do_shortcode, preg_replace_callback, do_shortcode_tag, WC_Shortcodes::checkout, WC_Shortcodes::shortcode_wrapper, WC_Shortcode_Checkout::output, WC_Shortcode_Checkout::order_pay, wc_get_template, include('/plugins/woocommerce/templates/checkout/order-receipt.php'), do_action('woocommerce_receipt_barclay'), WP_Hook->do_action, in /home/abc123/public_html/mysite.com/wp-includes/functions.php on line 5663

Notice: billing_address_1 was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), include('/themes/astra/page.php'), astra_content_page_loop, do_action('astra_content_page_loop'), WP_Hook->do_action, WP_Hook->apply_filters, Astra_Loop->loop_markup_page, Astra_Loop->loop_markup, do_action('astra_page_template_parts_content'), WP_Hook->do_action, WP_Hook->apply_filters, Astra_Loop->template_parts_page, get_template_part, locate_template, load_template, require('/themes/astra/template-parts/content-page.php'), the_content, apply_filters('the_content'), WP_Hook->apply_filters, do_shortcode, preg_replace_callback, do_shortcode_tag, WC_Shortcodes::checkout, WC_Shortcodes::shortcode_wrapper, WC_Shortcode_Checkout::output, WC_Shortcode_Checkout::order_pay, wc_get_template, include('/plugins/woocommerce/templates/checkout/order-receipt.php'), do_action('woocommerce_receipt_barclay'), WP_Hook->do_action in /home/abc123/public_html/mysite.com/wp-includes/functions.php on line 5663

Notice: billing_address_2 was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), include('/themes/astra/page.php'), astra_content_page_loop, do_action('astra_content_page_loop'), WP_Hook->do_action, WP_Hook->apply_filters, Astra_Loop->loop_markup_page, Astra_Loop->loop_markup, do_action('astra_page_template_parts_content'), WP_Hook->do_action, WP_Hook->apply_filters, Astra_Loop->template_parts_page, get_template_part, locate_template, load_template, require('/themes/astra/template-parts/content-page.php'), the_content, apply_filters('the_content'), WP_Hook->apply_filters, do_shortcode, preg_replace_callback, do_shortcode_tag, WC_Shortcodes::checkout, WC_Shortcodes::shortcode_wrapper, WC_Shortcode_Checkout::output, WC_Shortcode_Checkout::order_pay, wc_get_template, include('/plugins/woocommerce/templates/checkout/order-receipt.php'), do_action('woocommerce_receipt_barclay'), WP_Hook->do_action in /home/abc123/public_html/mysite.com/wp-includes/functions.php on line 5663

Notice: billing_country was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), include('/themes/astra/page.php'), astra_content_page_loop, do_action('astra_content_page_loop'), WP_Hook->do_action, WP_Hook->apply_filters, Astra_Loop->loop_markup_page, Astra_Loop->loop_markup, do_action('astra_page_template_parts_content'), WP_Hook->do_action, WP_Hook->apply_filters, Astra_Loop->template_parts_page, get_template_part, locate_template, load_template, require('/themes/astra/template-parts/content-page.php'), the_content, apply_filters('the_content'), WP_Hook->apply_filters, do_shortcode, preg_replace_callback, do_shortcode_tag, WC_Shortcodes::checkout, WC_Shortcodes::shortcode_wrapper, WC_Shortcode_Checkout::output, WC_Shortcode_Checkout::order_pay, wc_get_template, include('/plugins/woocommerce/templates/checkout/order-receipt.php'), do_action('woocommerce_receipt_barclay'), WP_Hook->do_action, in /home/abc123/public_html/mysite.com/wp-includes/functions.php on line 5663

Notice: billing_city was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), include('/themes/astra/page.php'), astra_content_page_loop, do_action('astra_content_page_loop'), WP_Hook->do_action, WP_Hook->apply_filters, Astra_Loop->loop_markup_page, Astra_Loop->loop_markup, do_action('astra_page_template_parts_content'), WP_Hook->do_action, WP_Hook->apply_filters, Astra_Loop->template_parts_page, get_template_part, locate_template, load_template, require('/themes/astra/template-parts/content-page.php'), the_content, apply_filters('the_content'), WP_Hook->apply_filters, do_shortcode, preg_replace_callback, do_shortcode_tag, WC_Shortcodes::checkout, WC_Shortcodes::shortcode_wrapper, WC_Shortcode_Checkout::output, WC_Shortcode_Checkout::order_pay, wc_get_template, include('/plugins/woocommerce/templates/checkout/order-receipt.php'), do_action('woocommerce_receipt_barclay'), WP_Hook->do_action, WP_ in /home/abc123/public_html/mysite.com/wp-includes/functions.php on line 5663

Notice: billing_phone was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), include('/themes/astra/page.php'), astra_content_page_loop, do_action('astra_content_page_loop'), WP_Hook->do_action, WP_Hook->apply_filters, Astra_Loop->loop_markup_page, Astra_Loop->loop_markup, do_action('astra_page_template_parts_content'), WP_Hook->do_action, WP_Hook->apply_filters, Astra_Loop->template_parts_page, get_template_part, locate_template, load_template, require('/themes/astra/template-parts/content-page.php'), the_content, apply_filters('the_content'), WP_Hook->apply_filters, do_shortcode, preg_replace_callback, do_shortcode_tag, WC_Shortcodes::checkout, WC_Shortcodes::shortcode_wrapper, WC_Shortcode_Checkout::output, WC_Shortcode_Checkout::order_pay, wc_get_template, include('/plugins/woocommerce/templates/checkout/order-receipt.php'), do_action('woocommerce_receipt_barclay'), WP_Hook->do_action, WP in /home/abc123/public_html/mysite.com/wp-includes/functions.php on line 5663