I'm getting ready to release the first version of our app, which is designed for existing (paying) customers of our service. The app will only have a Sign In functionality for the first few versions, ie users cannot create a new account through the app. We currently only have password or Google authentication through the website. I'm wondering how the app store guidelines apply here. It seems that since the March 4, 2020 update, Apple Sign In is required when using any other third party oauth providers (Google for our case). However I'm unclear if the listed exceptions cover this scenario. To state the obvious, users do not have a way currently to create an account with Apple Sign In, so exactly 0 users will ever succeed in logging in with that button if I'm required to put it. I understand the guidelines if we're talking about creating accounts, but since this is Sign In only, is it still required to provide as an option?
Thanks in advance!
