🐵 How to mint your own ERC-72 NFT

.env.example

API_URL="https://eth-rinkeby.alchemyapi.io/v2/xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
PRIVATE_KEY="0000000000000000000000000000000000000000000000000000000000000000"
ETHERSCAN_API_KEY="XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
CONTRACT_ADDRESS="0x0000000000000000000000000000000000000000"
TOKEN_URI="https://gateway.pinata.cloud/ipfs/XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"

deploy.js

main()

async function main () {
  try {
    const SusukidaNFT = await ethers.getContractFactory('SusukidaNFT')
    const susukidaNFT = await SusukidaNFT.deploy()

    console.info(`Contract deployed to address: ${susukidaNFT.address}`)
    console.info(`https://rinkeby.etherscan.io/address/${susukidaNFT.address}`)
  } catch (err) {
    console.error(err)
  }
}

hardhat.config.js

/** @type import('hardhat/config').HardhatUserConfig */

require('dotenv').config()
require('@nomiclabs/hardhat-ethers')
require('@nomiclabs/hardhat-etherscan')

module.exports = {
  solidity: "0.8.9",
  defaultNetwork: "rinkeby",
  networks: {
    hardhat: {},
    rinkeby: {
      url: process.env.API_URL,
      accounts: [`0x${process.env.PRIVATE_KEY}`],
    },
  },
  etherscan: {
    apiKey: process.env.ETHERSCAN_API_KEY,
  },
};

metadata.json

{
    "attributes" : [
      {
        "trait_type" : "Birthday",
        "value" : "August 27th"
      }
    ],
    "description" : "My name is Tatsuya Susukida.",
    "image" : "https://gateway.pinata.cloud/ipfs/QmToKYwMn35YeuK4J5Rn7pkuWG7Kq65rTdBATDCDR9cvpW",
    "name" : "Tatsuya Susukida"
}

mint.js

const {abi} = require('../artifacts/contracts/SusukidaNFT.sol/SusukidaNFT.json')

main()

async function main () {
  try {
    const {API_URL, PRIVATE_KEY, CONTRACT_ADDRESS, TOKEN_URI} = process.env
    const provider = new ethers.providers.JsonRpcProvider(API_URL)
    const signer = new ethers.Wallet(PRIVATE_KEY, provider)
    const contract = new ethers.Contract(CONTRACT_ADDRESS, abi, signer)

    const tx = await contract.mintNFT(signer.address, TOKEN_URI)
    await tx.wait()

    console.info(`https://rinkeby.etherscan.io/tx/${tx.hash}`)
  } catch (err) {
    console.error(err)
  }
}

SusukidaNFT.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.9;

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

contract SusukidaNFT is ERC721URIStorage, Ownable {
    using Counters for Counters.Counter;
    Counters.Counter private _tokenIds;

    constructor() ERC721("SusukidaNFT", "SNFT") {}

    function mintNFT(address recipient, string memory tokenURI)
        public onlyOwner
        returns (uint256)
    {
        _tokenIds.increment();

        uint256 newItemId = _tokenIds.current();
        _mint(recipient, newItemId);
        _setTokenURI(newItemId, tokenURI);

        return newItemId;
    }
}