Most of Jabber IM for linux registers xmpp protocol in system, so via clicking links like xmpp://user@example.com OS opens chat window with this contact. Will be good to see this feature in KDE Telepathy too. Reproducible: Always
Users can register this protocol manually, but I can't find command line or dbus command for open chat window with contact, having only contact jabber address.
Dear user, unfortunately Telepathy is no longer maintained. Please migrate to another solution, e.g. for Jabber a possibility is Kaidan, for Matrix a candidate is NeoChat.