As per the documentation:
response_type Required. The type of response requested. Valid values are code and id_token. You can request only code, or both code and id_token. Requesting only id_token is unsupported. When requesting id_token, response_mode must be either fragment or form_post.
This means that when requesting code and id_token, it should be possible to set the response_mode to fragment. However, when I do this and add the email and name scopes I get the following error:
"response_mode must be form_post when name or email scope is requested."
This makes it really hard to easily get information about the user's email and name on non-apple platforms in an efficient way. Furthermore, the returned ID token doesn't contain this information, which is something that should be present in ID token at least upon the first sign in.
Is there any way around this? Are there any plans to include such information in the ID token or allow response_mode=fragment or response_mode=query any time soon?