How to limit NFT creation to single token per Solidity contract

NFT
1

I’m working on a Solidity smart contract where I need to create exactly one unique NFT. Most guides I’ve found focus on creating collections with multiple tokens using ERC721 inheritance. Here’s my current implementation:

pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC721/extensions/ERC721URIStorage.sol";
import "@openzeppelin/contracts/utils/Counters.sol";

contract UniqueArtwork is ERC721 {

  uint256 public itemCount;
  constructor () ERC721 ("CatArt", "CAT"){
    itemCount = 0;
  }
  function mintArtwork(string memory metadataURI) public returns (uint256) {
    uint256 currentId = itemCount;
    _safeMint(msg.sender, currentId);
    _setTokenURI(currentId, metadataURI);
    itemCount = itemCount + 1;
    return currentId;
  }
}

What’s the best way to modify this code so it only allows minting one NFT total? I want to make sure nobody can call the mint function after the first token is created.