Please format it like this: [!community@instance.ml](/c/community@instance.ml), example: !technology@beehaw.org

This link is clickable on the Lemmy web interface, and will redirect you to the community within your own instance! It doesn’t work in the Jerboa app, I don’t know about other interfaces. Note that if your instance hasn’t had any users interact with the linked community yet, you’ll get a 404 error, and you’ll have to manually search !community@instance.ml to federate them.