You will find an "all-in" bet by entering the Play with Friends room and choosing the last entry fee. You can bet all your chips if you have at least 1,000,000 chips. The prize will be calculated automatically based on the chips you bet. Please note that in this room only you bet all your chips. The other players will play with the same entry fee as your all in, as well as for the same payout, and do not have the option to bet all their chips.