How to change database connection?

[an-amin]

I need to move the entire project to a different server.
I'm searching for the database configuration file but not finding it.
Which file does contain the database connection variables?

root@pondit:/var/www/kb.localhost/web# ls -l
total 156
drwxr-xr-x 31 web56 client5   4096 মার্চ  27 15:32 app
drwxrwxrwx  6 web56 client5   4096 আগস্ট   6  2021 assets
-rw-r--r--  1 web56 client5  61902 আগস্ট   6  2021 ChangeLog
-rw-r--r--  1 web56 client5    406 আগস্ট   6  2021 cli
-rw-r--r--  1 web56 client5   9505 আগস্ট   6  2021 config.default.php
-rw-r--r--  1 web56 client5   1562 আগস্ট   7  2021 config.php
drwxr-xr-x  3 web56 www-data  4096 মার্চ  27 15:30 data
-rw-r--r--  1 web56 client5  13094 আগস্ট   6  2021 favicon.ico
-rw-r--r--  1 web56 client5    263 আগস্ট   6  2021 index.php
-rw-r--r--  1 web56 client5     78 আগস্ট   6  2021 jsonrpc.php
drwxr-xr-x  9 web56 client5   4096 আগস্ট   6  2021 libs
-rw-r--r--  1 web56 client5   1090 আগস্ট   6  2021 LICENSE
drwxrwxrwx  2 web56 client5   4096 আগস্ট   7  2021 logs
drwxr-xr-x 13 web56 www-data  4096 মার্চ  14 16:48 plugins
-rw-r--r--  1 web56 client5     25 আগস্ট   6  2021 robots.txt
-rw-r--r--  1 web56 client5    374 আগস্ট   6  2021 SECURITY.md
drwxr-xr-x 21 web56 client5   4096 মার্চ  27 00:03 stats
drwxr-xr-x 11 web56 client5   4096 আগস্ট   6  2021 vendor
-rw-r--r--  1 web56 client5    793 আগস্ট   6  2021 web.config

[an-amin]

got it in the config.default.php file.

define('DB_DRIVER', 'mysql');
define('DB_HOSTNAME', 'localhost');
define('DB_USERNAME', '');
define('DB_PASSWORD', '');
define('DB_NAME', '');
define('DB_PORT', null);
define('DB_SSL_KEY', null);
define('DB_SSL_CERT', null);
define('DB_SSL_CA', null);
define('DB_VERIFY_SERVER_CERT', null);
define('DB_TIMEOUT', null);