So the guy I bought it from had 4 Husky c-clamps.... yes; you read that right. that worked until I bought
these.
"LEER J Bolt Clamp, Set of 4" on Amazon
[I have a 2020 non ram-box model, these clamps
don't interfere with with the factory bed utility track that came on my truck]
Check the gasket on the used one; I have purchased some off Amazon before; I like the rubber double bulb type, you can also you the flat lay tape kind but YMMV.
Ive even seen some guys black silicon seal in some areas that need more attention.
EDIT: Forgot to say; I ended up rubbing some paint off the very top of the tailgate in the corners due to fitment on the way back from buying it; so I added a rubber double bubble seal to the glass enclosure to limit that again; FYI.
painters tape doesnt work too well as a mitigation