Var provider As New ASAuthorizationAppleIDProviderMBS
Var request As ASAuthorizationAppleIDRequestMBS = provider.createRequest
Var controller As New ASAuthorizationControllerMBS(Array(request))
Break

You use a provider to create a request (ASAuthorizationAppleIDRequestMBS), which you then use to initialize a controller (ASAuthorizationControllerMBS) that performs the request.

On success, the controller’s delegate receives an authorization (ASAuthorizationMBS) containing a credential (ASAuthorizationAppleIDCredentialMBS) that has an opaque user identifier. You can use that identifier to later check the user’s credential state—for example, to see if authorization has been revoked—by calling the getCredentialState method.

You need to have a code signed application with the entitlement com.apple.developer.applesignin and a matching mobile provision profile for the application. The easiest way to setup a profile may be to make a dummy applicaiton in Xcode with the same name, bundle identifier and entitlements.
Subclass of the ASAuthorizationProviderMBS class.