Yesterday my son signed out of his Apple ID that he was using on his phone. He has no idea what the user name or password is. He has now lost his Apple Music playlists? Can these be retrieved on the Apple Music app using his phone number?
If you forgot your Apple ID - Apple Support. He would at least get monthly emails for the subscription, when the Apple ID is the same as the email address to where that message is send. The Apple ID is repeated in the invoice message body.
If you forgot your Apple ID password - Apple Support
If he signs in again, then the Apple Music subscription service will resume, and his iCloud Music Library and playlists will come back.
Lost my Apple Music playlists
