If you have the bike rack receiver hitch on your Landmark, it's 1 1/4" and would generally be considered a Class I hitch. But the Heartland application is to use it for a bicycle rack, not for towing.
You might think that since 1 1/4" receivers are Class I, it would allow you to load it with up to 200 # tongue weight and 2000# towing weight, but that's only a general statement about class I receivers. The receiver is attached to the frame of the RV and is only as good as the weakest link. Lippert says that you could damage the frame by towing anything and that towing would void the frame warranty.