Add amazon s2s docs

docs/platform-resources/server-notifications.md

@@ -16,7 +16,7 @@ RevenueCat does not require Platform Server Notifications from the App Store or
 - Apple App Store Server Notification: [Setup →](/platform-resources/server-notifications/apple-server-notifications) (Optional)
 - Google Real-Time Developer Notifications: [Setup →](/platform-resources/server-notifications/google-server-notifications) (Optional)
 - Stripe Server Notifications: [Setup →](/platform-resources/server-notifications/stripe-server-notifications) (Required for Stripe)
-- Amazon Appstore: Not yet supported in RevenueCat.
+- Amazon Appstore Real-time Notifications: [Setup →](/platform-resources/server-notifications/amazon-server-notifications) (Optional)
 
 ## Confirming Connection
 

docs/platform-resources/server-notifications/amazon-server-notifications.md

@@ -0,0 +1,45 @@
+---
+title: Amazon Appstore Real-time Notifications
+slug: amazon-server-notifications
+excerpt: Sending Amazon Appstore real-time notifications to RevenueCat
+hidden: false
+---
+
+RevenueCat does not require server notifications from Amazon Appstore, however doing so can speed up webhook and integration delivery times and reduce lag time for [Charts](/dashboard-and-metrics/charts).
+
+:::warning Receipt must exist in RevenueCat
+Amazon Appstore Real-time Notifications only work if the receipt exists in RevenueCat when the event is dispatched from Amazon Appstore. If the receipt doesn't exist, the event will fail.
+:::
+
+## Setup Instructions
+
+1. Navigate to your **app settings** in the RevenueCat dashboard by selecting your app from **Project Settings > Apps**.
+2. Expand the **Amazon Real-time Notifications settings** section and copy the endpoint provided under **Amazon Real-time Notifications URL**.
+
+![Copy the Amazon Real-time Notifications URL from RevenueCat](/images/amazon/amazon_s2s_copy_url.png "Copy the Amazon Real-time Notifications URL from RevenueCat")
+
+3. Go to the [Amazon Appstore Console](https://developer.amazon.com/apps-and-games/console/apps/list.html) and select your app.
+
+4. Click **App Services** in the left sidebar and under **Real-time Notifications**, expand **Add an Endpoint**.
+
+![Navigate to App Services in the Amazon Appstore Console](/images/amazon/amazon_s2s_appstore_menu.png "Navigate to App Services in the Amazon Appstore Console")
+
+5. **Paste** the URL of the endpoint you copied from the RevenueCat dashboard and click **Submit**.
+
+![Submit the endpoint URL in Amazon Appstore Console](/images/amazon/amazon_s2s_appstore_submit_url.png "Submit the endpoint URL in Amazon Appstore Console")
+
+6. In a few seconds, a label should appear saying **Verified**, confirming that the endpoint was added successfully.
+
+![Endpoint verification status in Amazon Appstore Console](/images/amazon/amazon_s2s_appstore_verified.png "Endpoint verification status in Amazon Appstore Console")
+
+7. In the RevenueCat dashboard, you should see a **Received at** timestamp for the endpoint too.
+
+![Last received timestamp in RevenueCat dashboard](/images/amazon/amazon_s2s_last_received_at.png "Last received timestamp in RevenueCat dashboard")
+
+## Troubleshooting
+
+If you don't see the **Verified** label in the Amazon Appstore Console, confirm that you copied the correct URL from the RevenueCat dashboard and click **resend** to try again.
+
+![Resend notifications option in Amazon Appstore Console](/images/amazon/amazon_s2s_appstore_resend.png "Resend notifications option in Amazon Appstore Console")
+
+If the issue persists, contact [support](https://app.revenuecat.com/settings/support).