If you'd like to get into trouble, you can try to sell your account. I wonder what the thinking behind this is. We can assume that your account represents a certain value on a site, you have not reached that value just like that? I also don't think an interested player would pay a lot of money for this. And it could also be a scam from buyer or seller. I do not advice this.
For what kind of trouble for seller? Most the gambling casino account don't requires any KYC or any info regarding the owner. Just an email and password then you are good to go. The main benefits for this kind of account are the bonus on each milestone you achieved. Like on betfury, You can claim there tokens in equivalent to your level, The higher level means the higher token you will get when you reach a certain milestone.
I believe this deal can only possible if they hire an escrow that will secure the account for buyer by changing it's email password and the account security such as 2FA.