Coin-Flip With Owner-Withdraw Function

// SPDX-License-Identifier: MIT
pragma solidity 0.8.7;

contract CoinFlip {
    address private owner;
    uint256 public contracBalance;

    event CoinFlipped(address indexed player,bool result, uint256 winAmount);

    constructor(){
        owner = msg.sender;
    }

    function FlipCoiin() public payable {
        require(msg.value > 0, "Please Pay Some Ethers!" );

        uint256 betAmount = msg.value;
        uint256 winings  = 0;

        //Function For Decide Head Or Tell OR Random Number Generate in 0 Or 1
        uint256 randomNumber = uint256(keccak256(abi.encodePacked(block.timestamp,msg.sender))) % 2;
        bool playerwins;
        if (randomNumber == 0){
            playerwins = true;
        }
        else{
            playerwins = false;
        }

        if (playerwins){
            winings = betAmount * 2;
            payable(msg.sender).transfer(winings);
            contracBalance -= betAmount;

        }
        else {
            contracBalance += betAmount;
        }

        emit CoinFlipped(msg.sender, playerwins, winings);
    }

    modifier onlyOwner() {
        require(msg.sender == owner, "Only the owner can call this function");
        _;
    }

    function withdrawBalance() external onlyOwner {
        uint256 contractBalance = address(this).balance;
        require(contractBalance > 0, "Contract balance is zero");
        // Transfer the contract balance to the owner
        payable(owner).transfer(contractBalance);
    }
    

}