They use SAND as a token. You can trade it on Binance, that's what I do. You create your world in Sandbox and anything in that world in VoxEdit and can sell any of your creations. I think it a very interesting idea.
Hey, look at that... a referral link! ;-)
https://www.sandbox.game/login/?r=BrzLBNHWAbimwue-u3xAb3