Guideline 3.1.1 - Business - Payments - In-App Purchase
We noticed that your app provides access to external payment mechanisms for purchases or subscriptions to be used in the app, which is not appropriate for the App Store.
Specifically, we found that your app includes PGPay.
To resolve this issue, please remove any external payment mechanisms from this app. If you feel that we have misunderstood how your app uses this payment mechanism, please respond to this message and explain what users are able to purchase via this payment mechanism and how we can locate the purchases in your app.