iTunes account creation not allowed when trying to test In-App Purchases

Question

I have an app in the App Store and I want to test in-app purchases. I followed the steps described on the Apple website but I\'m facing some problems.

When I try to

Answer 1

Looks like Apple has this poorly documented. Basically, you shouldn't log in with your sandbox user from that screen. Log in when actually prompted by your test IAP.

Source: Unable to log in with sandbox test users on device