sorry i was wrong, that url does not contain the direct apk link as that part of the page is probably generated via the api.
you'd wanna put `https://api.damus.io/damus-android-install-instructions` as the app source url and also `\d.\d.\d+` as the version string extraction regex which might or might not need adjusting with future versions. :)
hope it helps.
cc: nostr:npub1fhpw2ux9flhcxyl6xp84996qgnkkcy59zqzjvq9fhpxcx7upymus69ds8n