Apple ID cannot be used to create an account in other apps
When I try to sign in it says: Your Apple ID cannot be used to create an account in other apps, what does that mean and how do I solve it?
iPhone 8, iOS 14
That message is related to this Apple service:
What is Sign in with Apple? - Apple Support
You may not have features set on your account to use the service. See this article for more about that: