I've been fighting this issue for 3 days now. After several failures, I created a new app id and service id yesterday. I checked and entered domain, callback, and login usage clearly, but it keeps returning an error. Can you help me figure out what's wrong? https://appleid.apple.com/auth/authorize?response_type=code&client_id=com.smoothmail.signin&redirect_uri=https%3A%2F%2Fsmoothmail.store%2Fapple-auth&state=4157daa763&scope=name+email&response_mode=form_post