If you have access to RBoy Apps, then see the Door Lock Code User Management smartapp which can play notifications directly to a connected speaker like R1 or Sonos.
However, this will send preset notifications (User X unlocked the door, or Door was left open for too long or Door was manually locked etc).
If you want a complete custom setup then you may want to consider using WebCoRE or CoRE to create the rules. It should be fairly straight forward if you’re creating a simple rule.