You’d want to make example.com an SSO provider, and then use it to log in to Discourse — Official Single-Sign-On for Discourse (sso)
How to do this would vary based on what you’re using to manage logins for example.com.
You’d want to make example.com an SSO provider, and then use it to log in to Discourse — Official Single-Sign-On for Discourse (sso)
How to do this would vary based on what you’re using to manage logins for example.com.