Sign in with Apple is a new iOS feature which lets users sign in to an application using an Apple ID. According to the Apple review guidelines you must support Sign in with Apple if your app:
“…use a third-party or social login service (such as Facebook Login, Google Sign-In, Sign in with Twitter, Sign In with LinkedIn, Login with Amazon, or WeChat Login) to set up or authenticate the user’s primary account with the app must also offer Sign in with Apple as an equivalent option.”
The Defold extension for Sign in with Apple API integration has been released and is ready for end-user testing: