Can't use a sandbox account

I do the following steps:

  1. Connects to the sandbox account through the settings
  2. Installing the app from a test flight
  3. Trying to subscribe to the app

payment pop-up opens with my Apple ID and not with the sandbox account

I am using iPhone 12 iOS 16.3.1

I'm having the same error and couldn't find a solution.

Can't use a sandbox account
 
 
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