LL2500HD

Hi, new member and new owner of a 2020 2500HD. I have the Z82 trailering package and I'm trying to determine if there is an adapter or other end on the 5th wheel wiring. I haven't crawled under to find the loom which I understand is above the rear bumper. Want to order the plug for the bed and need to know what to order. Anybody have the answer? I'm having a tough time finding this info on Chevy's official site. Thanks in advance.