For a toy hauler like your 2020 Heartland RV Lithium, you need to use an expandable hitch since these are not custom made.
The Curt Adjustable, part # 13703, is a good choice. It expands from 22" to 72" and attaches to the frame of your toy hauler by either bolting or welding on. You need to check the width of your frame to ensure that it falls within that 22" to 72" range. It works with box frames, C-channel frames, or I-beam frames, and it gives you a 2" receiver. I've linked to a video... view full answer...