A hitch haul has a 2" box tube bolted under it that slides into the truck hitch , remove it and replace it with a longer piece of box to extend it back .
For more stability what I did on one that I used behind the camper like that was add some light chain or cable and turnbuckles from the rear most corners of the hitch haul up to the jack brackets on the camper, that took the side to side slop out and it made a nice platform at the rear of the camper
If you just use the hitch haul without the extention under the camper you can still get chairs and extra junk in it