Back in 2013 -16 that 1.25" factory installed receiver was an option. It was made by lippert as we had one on our big horn. That thing was so flimsy, it wobbled like crazy. I removed ours and welded a lot more support on it. and it still was too thin and flimsy to trust. On our fifth wheel, that hitch flexed and wobbled so bad, it broke three bike racks and dumped our bikes that many times even after I added more support to it.
I would very much suggest you have some welding place add a 2" receiver on the back and forget that bolt on joke.