Cannot get name & email with sign in with Apple on real device

If someone fails in storing "user email", "first-name" first time, then he should follow the following steps:

iPhone Settings -> Apple Id -> Password & Security -> Apple ID logins -> {YOUR APP} > Stop using Apple ID.

Problem solved! tl;dr

This is an expected behavior

Answered by Apple Engineer (Original post link: https://forums.developer.apple.com/thread/121496)

Hi aslkdjalksdjasdasd,

This behaves correctly, user info is only sent in the ASAuthorizationAppleIDCredential upon initial user sign up. Subsequent logins to your app using Sign In with Apple with the same account do not share any user info and will only return a user identifier in the ASAuthorizationAppleIDCredential. It is recommened that you securely cache the initial ASAuthorizationAppleIDCredential containing the user info until you can validate that an account has succesfully been created on your server.

Patrick

2019/12/15 Edit

This behavior is also documented on Apple's Sign in with Apple doc, check the documentation.

Ensure that your app relays the credentials and user information to your app servers. The API collects this information and shares it with your app the first time the user logs in to the app using Sign in with Apple. If the user then uses Sign in with Apple on another device, the API doesn't ask for the user’s name or email again. It collects the information again only if the user stops using Sign in with Apple and later reconnects to your app.