i'm following the official example here:
from allauth.socialaccount.providers.github.views import GitHubOAuth2Adapter
from allauth.socialaccount.providers.oauth2.client import OAuth2Client
from dj_rest_auth.registration.views import SocialLoginView
class GitHubLogin(SocialLoginView):
adapter_class = GitHubOAuth2Adapter
callback_url = CALLBACK_URL_YOU_SET_ON_GITHUB
client_class = OAuth2Client
```but i have no clue what the callback url should be