Yes you can if you have a crypto-wallet -- you can't do it on this site, but you convert to ETH then into cash. You will find more info in Member Support :)
This is a cryptocurrency auction site for Ink Protocol XNK only -- Nothing sells for cash/money on Listia. You'll need to read "How it works" and the Policies. But if you want money then you should delete this and find a venue that takes $$ =_)