Azure Active Directory (AAD) B2C is supporting more and more third party identity services.
After adding support for GitHub or WeChat, Azure AD B2C is now supporting Apple ID.
This support comes following Apple’s announcement that all applications in the Apple App Store which support third-party sign-in will require to include Apple ID (see https://developer.apple.com/news/?id=06032019j).
To implement this support in your application using Azure AD B2C, you will use the OpenID Connect identity provider. All documentation is available here https://github.com/azure-ad-b2c/samples/tree/master/policies/sign-in-with-apple