Custom source type

[waclaw66]

Hi!
I would like to implement login via my country local OAuth2 provider (seznam.cz). Unfortunatelly I'm unable to configure that, becuse it uses special scope called "identity" without common identification field like "id" or "sub", it has own field "oauth_user_id".
Is there a way how to create own source type like patreon or override user identification field?
Thanks in advance.

[waclaw66]

Could be property mapping applied also for OAuthCallback.get_user_id as workaround?
Another solution would be to add custom user_id field name to specify within OAuth source.
Currently there are accepted only id or sub as user identification field of OpenID OAuth Source, which is quite limiting.