Hi, I'm trying to integrate 'Sign in with Apple' in my application. I have my app identifier: 'com.ameedsayeh.apple' with 'sign in with apple' capability enabled for that app. 2. then I created Service ID to use: 'com.ameedsayeh.apple.signin' and configured the service to the app identifier above. 3. I created a key for the app. Now each time I try to GET this url PLAIN https://appleid.apple.com/auth/authorize? response_type=code & response_mode=form_post & client_id=com.ameedsayeh.apple.signin & redirect_uri=my_api_end_point & state=319a1fefa4 & scope=name+email I keep getting invalid_client message and I've been trying since yesterday! I tried recreating many apps, services, keys over and over again but with no success. I also tried to do it via AWS Amplify Cognito and it's showing the same. This is the PHP code I use to create the URL for testing ?php session_start(); $redirect_uri = 'end_point'; $client_id = 'com.ameedsayeh.apple.signin'; $_SESSION['state'] = bin2hex(random_bytes(5)); $authorize_url = 'https://appleid.apple.com/auth/authorize'.'?'.http_build_query([ 'response_type' = 'code', 'response_mode' = 'form_post', 'client_id' = $client_id, 'redirect_uri' = $redirect_uri, 'state' = $_SESSION['state'], 'scope' = 'name email', ]); echo $authorize_url; echo 'a href="'.$authorize_url.'"Sign In with Apple/a'; ? This is really disappointing and blocking, please help!