Payable counter contract to increment/decrement. This accepts Ethers in order to run the functions and the owner has the capability to withdraw funds generated from running the increment/decrement function

Counter.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

contract Counter {
    uint public count;
    address payable owner;
    uint256 public FEE = 2 ether;

    constructor() payable {
        owner = payable(msg.sender);
    }


    // Function to get the current count
    function get() public view returns (uint) {
        return count;
    }

    // Function to increment count by 1
    // @notice - Caller of this function need to pay 1 Ether in order to run this.
    function inc() public payable {
        require(msg.value == FEE, "Need to send 2 ether in order to run this function");
        count += 1;
    }

    // Function to decrement count by 1
    // @notice - Caller of this function need to pay 1 Ether in order to run this.
    function dec() public payable {
        // This function will fail if count = 0
        require(msg.value == FEE, "Need to send 2 ether in order to run this function");
        count -= 1;
    }

    // @notice Fetch the current contract balance or total ethers sent to this contract 
    function getBalance() public view returns(uint256) {
        return address(this).balance;
    }

    modifier shouldBeTheOwner() {
        require(msg.sender == owner, "You should be the owner of this running in order to withdraw funds!");
        _;
    }

    // @notice Withdraw function. This will withdraw all the funds from the contract from the minting
    function withdraw() public shouldBeTheOwner {
        require(address(this).balance > 0, "Contract Balance: 0; Nothing to withdraw here!");
        payable(msg.sender).transfer(address(this).balance);
    }


}