It holds the bumper cover on the truck.

The non hitch part will not allow the cover to get close enough to get the mounts to reach the bumper.

It was hard with the correct one to get the cover on.

Unfortunately, the bumper carrier [if you mean the long replacement bumper covered by the plastic bumper cover [d in the parts list, shown in picture G in the official install document] is quite different than the even heavier bumper carrier it replaces. you gotta have it. Be sure and get the two plastic 'cups' that go on the end, too, and don't disconnect them from the scavenged bumper carrier. Their install is counterintuitive. You have the install document, right?

For the record, I wanted to add that the stock bumper carrier and the hitch bumper support are not all that different. The stock one has thick addition of steel. It would be possible to cut out the steel and use a stock bumper support with the OE hitch, if needed.