I answered assuming that the house belongs to a friend or loved one, or that I have some important reason I want the occupant's immediate attention. In those si

I answered assuming that the house belongs to a friend or loved one, or that I have some important reason I want the occupant's immediate attention. In those situations, I'd knock. I do very strongly prefer a QR code thing to something like a Ring (as long as the QR code isn't going to a service such as Ring), though, but neither is better than knocking.