On FlipContract.sol user not get paid after winning

I’m learning from this Video

user is receiving receipt :: “win” & “loose”, but not get paid when he win.

I copied codes from https://github.com/MoralisWeb3/demo-apps/blob/main/casino-dapp/truffle/contracts/flipcontract.sol
maybe this code is not working properly:
line no 23: “payable(msg.sender).transfer(msg.value * 2)”

what may be my mistake ?

That code should transfer prize in case of wining. You could look in ganache on events to see if that transfer was executed.