An authenticated name and email will never be included as separate fields in the decoded id_token because (quote):

The modified name is only shared with your app and not with Apple, and hence isn’t included in the ID token.
https://developer.apple.com/documentation/signinwithapplerestapi/authenticating_users_with_sign_in_with_apple

Instead they should be present in json response under separate key ‘user’. Note, it will be there only the first time user logs in as per (quote):

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.
https://developer.apple.com/documentation/signinwithapplerestapi/authenticating_users_with_sign_in_with_apple