This apple sign in is horrible and I am stuck when apple ask to use sign in with apple id as equivalent because I am using google sign in. I face the same issue here. If we store it locally to the mobile we are able to detect in database which email is sign in. and update the time login or use it for other purpose. But the problem is when user change their device and try to sign in with the same apple id, how we know that the sign in is from the same apple id as before since the sign in response like email only return once for the first time ?
This is not a good experience and workflow to sign in.