As far as I know, you can sell skins and play on different gambling sites. By the way, my friend recently won about $ 500 on one of these
csgo gambling sites, but it seems to me that he was fortunate because I had been playing before and constantly only lost. But if you win something, then you can transfer money to your bank card. You should watch a video about it on YouTube or just Google it, and you will find detailed information. I hope my post helped you, and now you understand that you can sell skins in cs go without any problems. Good luck to you, man.