The message is that rental companies don’t WANT you towing anything!!!
Small percentage of the consumer public have experience with proper hook-up, let alone towing on the open road.
Scoot your butt down to a U-Haul shop, talk w the manager and read the specs.
Then plan on waiting a week or two for the one you need to become available.
It’s pretty good bet that someone needing to ask where to rent said equipment is lacking the requisite skill set to handle same.