Here is FortuneJack's hot wallet: https://www.walletexplorer.com/wallet/0000b2d125cddfaa/addresses
As of this post, there is a balance of 41.39BTC.
Bitcoin doesn't have smart contracts to the extent of some altcoins. My understanding is that the prize will go to the winner's FortuneJack balance, and they can bet it/withdraw it as they see fit. The wallet is proof that they can afford to pay it out.