When Sign in with Apple was announced it was stated it wouldn't be a requirement until April 2020. As per https://developer.apple.com/news/?id=09122019b https:

When Sign in with Apple was announced it was stated it wouldn't be a requirement until April 2020. As per https://developer.apple.com/news/?id=09122019b https://developer.apple.com/news/?id=09122019b