hedgedoc/docs/guides/auth/oauth.md

OAuth general information

service	callback URL (after the server URL)
facebook	/auth/facebook/callback
twitter	/auth/twitter/callback
github	/auth/github/callback
gitlab	/auth/gitlab/callback
mattermost	/auth/mattermost/callback
dropbox	/auth/dropbox/callback
google	/auth/google/callback
saml	/auth/saml/callback