itch.io

I actually did something like this in Resonite with another avatar: when I go AFK or view another world, a substitute doll will replace the avatar.

Guess I get to do it again!

Bruh, no matter which crypto you use, you are going to pay more than the original value in just transaction fees.
Also, people don't have to accept a currency they don't want, and that also includes cryptocurrencies. Not to mention, itch.io won't back outside done transactions.
Since you are that concerned about remaining anonymous, you also have effectively agreed that some services will not be available to you. Congrats, but you have found another that isn't available to anonymous users.