简单来说：
就是如果你的APP里有第三方登录，那么就得把苹果的apple Id登录也作为第三方登录的一种，而且要放在其他第三方登录的前面，否则审核就不要你过。
下面的博客讲得比较全面，而且附上了接入的代码和相关连接：
苹果给我发的邮件内容
Sign in with Apple makes it easy for users to sign in to your apps and websites using the Apple ID they already have. Users love the simplicity and privacy of Sign in with Apple, and many developers are seeing improved adoption rates as a result. And now, it’s even simpler to implement this feature and communicate with your users.
Please note that all apps that authenticate or set up user accounts must support Sign in with Apple if required by guideline 4.8 of the App Store Review Guidelines. New apps must follow guideline 4.8 and Human Interface Guidelines on Sign in with Apple starting April 30, 2020. App updates must follow these guidelines starting June 30, 2020.
