The simplest NFT contract you'll ever find

NFT.sol

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

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

contract NFT is ERC721URIStorage {
    constructor(
        string memory _name,
        string memory _symbol,
        string memory _metadataUrl
    ) ERC721(_name, _symbol) {
        _safeMint(msg.sender, 1); // Token ID 1
        _setTokenURI(1, _metadataUrl);
    }

    function contractURI() public view returns (string memory) {
        return tokenURI(1);
    }
}