I’m on 0.17.0 and according to the docs Kopia has a really good looking notification command. Using it is proving to be a challenge, as I keep on getting this: kopia: error: expected command but got "notification", try --help.
Neither --help nor --help-full have anything on notification. Hence, is it implemented?
Try installing from the latest git commit. I think you’ll find that notification is in a pre-release state. Skimming the git log shows some very recent activity to make it available in both CLI & UI.
The recent code seems to have the capability, in the CLI at least, for notifications via email, Pushover (the 3rd party service) and webhooks.