To be honest I didnt have a clue but I Google it and got,
No, Chess.com generally does not allow users to post for-sale listings for physical items, as the site is intended for personal, non-commercial use, and its Terms of Service prohibit "sell[ing], trade[ing], resell[ing] or exploit[ing]... any portion of the Service for any commercial purposes".
Could be wrong but probably not.
No problem. I wonder if they would allow the Ebay link as kind of a psa for those interested in it.
Google again
Yes, you can typically post an external eBay link on Chess.com, but its clickable status and visibility will depend on the specific context (like a forum post or a message) and Chess.com's and eBay's policies regarding external links. You will need to ensure your post adheres to the community guidelines of Chess.com and be aware that eBay itself may restrict external links in listings for promotional purposes.
Again could be wrong, im sure you will sort it out.
May I suggest utilizing the "...search forum topics..." field within the right-hand sidebar of the PC/desktop interface for a keyword search? It is akin to a Pro Tip that can save you aimless surfing.
There is a thread, dating back to 2018, that is active every so often entitled (literally):
> > > Chat here if you have any chess sets to sell. < < <
Couple clicks, search, read, post wisely and 
. GL in your refined chess.com forums searching.
I've got a barely used, one year old Chess Classics Exclusive Chess Computer by Millennium and the Millennium Chesslink that I was going to Ebay but wondered if a Chess Forum might be better, if it was allowed. I thought I was going to do more OTB, but that just wasn't the case. It's a great electronic board, and I'd highly recommend it, but I just don't play it enough to keep.