A smart contract that allows only the contract owner to perform an action

Ownable.sol

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

contract Ownable {
  address public owner;

  constructor() {
    owner = msg.sender;
 }

 
modifier onlyOwner() {
    require(msg.sender == owner, "not owner");
    _;
 }
 
 function setOwner(address _newOwner) external onlyOwner {
    require(_newOwner != address(0), "invalid address");
    owner = _newOwner;
 }
 
 function onlyOwnerCanCall() external onlyOwner {
 // code
 }
 
 
function AnyOneCanCall() external {
 // code
 }
 
}