S. Extend Downwards on the column bolts.? I also have full size pick -up, 2010 new to me,, specialty tow shop installed the Bed Hitch B & M , not cheap , but can remove the 2 5/16 ball sleeve to get flat bed, if moving furniture, etc.
At home I also wrench loosen the TWO column bolts & lowered the hitch for
more height clearance.. It would be easier to vertical jack up if one removed the truck tailgate when towing. Some people use a Mesh net & another option is a Louvered gate with the v top notch cut down.