I have a receiver type hitch complete with mounting hardware and lighting harness (worth $40 itself). In excellent condition. Fits 2017 - 2021 model years. Local pickup only. (I might be able to meet you within 25 miles for another $20)
Here are the details on the wiring harness:
You might need to replace the wire clamps since mine were used once. They're the 4 little blue items in the pic on Amazon. If you want to power it directly from the Bolt's 12V battery you'll also need wire and an inline 15A fuse/holder:
Here are the details on the wiring harness:

Amazon.com: Tekonsha 119147 ModuLite HD Protector Trailer Light Power Module : Automotive
Buy Tekonsha 119147 ModuLite HD Protector Trailer Light Power Module: Lighting - Amazon.com ✓ FREE DELIVERY possible on eligible purchases
www.amazon.com
You might need to replace the wire clamps since mine were used once. They're the 4 little blue items in the pic on Amazon. If you want to power it directly from the Bolt's 12V battery you'll also need wire and an inline 15A fuse/holder: