Why cant I get a 2" hitch ball that fits my truck without buying a reciever? on 2010 Toyota Tacoma

Available hitch balls are not long enough to bolt thruogh the bumper.

Asked by for the 2010 Toyota Tacoma
Buy one from Toyota if it has the spot on the bumper for the hitch ball. If is not etched on the bumper then you need to get receiver put on. That would be best to do anyways.