Receipt Verification Service (RVS) enables validation of purchases made by your app's users from your own server. Amazon recommends calling RVS from only a secure server, because it hosts the shared secret. You should not call this service from your app.
The following workflow describes the basic process for verifying purchase transactions:
- An user completes an in-app purchase.
- Get the receiptID returned to the onPurchaseResponse() callback.
- Send the transaction's userId and receiptId from your app to your server.
- Send a request from your server to RVS to verify the receipt.
- Send the result of the RVS verification back to your app.
- If the receipt is valid, fulfill the item. Note that this can mean to fulfill an in-game consumable, non-consumable, or to push content to a device for a subscription.
Please check here for more information: https://developer.amazon.com/public/apis/earn/in-app-purchasing/docs-v2/verifying-receipts-in-iap-2.0
Keywords: IAP, RVS, Receipt Verification Service