There are tons of threads on this subject. It depends on the TT as to whether it is OK to mount a trailer hitch for this type of carrier. Most of the time, esp on newer and/or 'lite' models, the the bumpers aren't made to carry more than the weight of the spare tire, and adding any type of cargo carrier/hitch etc will void the warranty.
However, there are folks who have done this - some by adding additional welds/supports to the bumper, etc. Do a search for cargo carrier or bumper hitch and you'll find a lot of threads...
2012 Flagstaff V-lite 30 WTBS
2011 Ford Expedition
4 kids and a hubby & never enough time to camp!
2011: 17 nights 2012: 26 nights 2013: 46 2014: 20 2015: 16