Cabinet hanger, For mounting in drilled hole, keyhole slot

Dritz Wood Keyhole Slot Quilt Hangers keyhole slot hanger How to install a keyhole hanger Keyhole hangers: https Keyhole Slot Hanging keyhole slot bit What is the proper way to install these keyhole picture hangers? If they are surface mounted, doesn't there have to be a hole or slot for

keyhole slot The empty file slot was changed from Empty to New Save File Characters A keyhole and a hinge have been added to it Labels have been added to