Since China cannot use Google and Facebook services, Chinese players must use a VPN when logging in to IF. I hope you can add login systems other than Google, Facebook, and Twitter, such as Baidu or Bing, or build your own login system :)
This is a known request and the “apple sign-in” has been said that it will be implemented soon, with hopefully new ways to sign in.
Android users will not be able to log in with apple. :)
We’re aware of this and working towards it. We will add Sign in with Apple (works on both platforms) as an initial start. Cheers!