In App Purchases Not working in iOS

Hello Everyone,

I am working on a Unreal Engine based Mobile game and have in-app purchases included. Over Android, It all worked fine, and in-app purchases is working too and app went Live.

But over iOS, I am facing issues, The in-app purchases don’t work at all, I don’t get any response after clicking on Buy button.

If I submit the app over Store for review, I get following reply from Apple:

We found that your in-app purchase products exhibited one or more bugs when reviewed on iPad running iOS 14.7.1 on Wi-Fi.

Specifically, when we tapped on your in-app purchase no further action occurred.

Next Steps

When validating receipts on your server, your server needs to be able to handle a production-signed app getting its receipts from Apple’s test environment. The recommended approach is for your production server to always validate receipts against the production App Store first. If validation fails with the error code “Sandbox receipt used in production,” you should validate against the test environment instead.

Here is my IOSEngine.ini file :

The Status of my In app purchases is “Waiting for Review”

What do I need to get the In app purchases work?

I have followed this tutorial for Implementing In app Purchases: