An identifier associated with the user’s Apple ID.
- iOS 13.0+
- macOS 10.15+
- Mac Catalyst 13.0+
- tvOS 13.0+
- watchOS 6.0+
Typically you leave this property set to
nil the first time you authenticate a user. Otherwise, if you previously received an authorization containing an
ASAuthorization instance, set this property to the value from the credential’s
The value is an arbitrary string that’s portable among apps from a single developer, but not between apps from different developers.