How to Mint Tokens

import {
  clusterApiUrl,
  Connection,
  PublicKey,
  Keypair,
  Transaction,
  sendAndConfirmTransaction,
} from "@solana/web3.js";
import {
  createMintToCheckedInstruction,
  mintToChecked,
} from "@solana/spl-token";
import bs58 from "bs58";
 
(async () => {
  // connection
  const connection = new Connection(clusterApiUrl("devnet"), "confirmed");
 
  // 5YNmS1R9nNSCDzb5a7mMJ1dwK9uHeAAF4CmPEwKgVWr8
  const feePayer = Keypair.fromSecretKey(
    bs58.decode(
      "588FU4PktJWfGfxtzpAAXywSNt74AvtroVzGfKkVN1LwRuvHwKGr851uH8czM5qm4iqLbs1kKoMKtMJG4ATR7Ld2",
    ),
  );
 
  // G2FAbFQPFa5qKXCetoFZQEvF9BVvCKbvUZvodpVidnoY
  const alice = Keypair.fromSecretKey(
    bs58.decode(
      "4NMwxzmYj2uvHuq8xoqhY8RXg63KSVJM1DXkpbmkUY7YQWuoyQgFnnzn6yo3CMnqZasnNPNuAT2TLwQsCaKkUddp",
    ),
  );
 
  const mintPubkey = new PublicKey(
    "8mAKLjGGmjKTnmcXeyr3pr7iX13xXVjJJiL6RujDbSPV",
  );
 
  const tokenAccountPubkey = new PublicKey(
    "2XYiFjmU1pCXmC2QfEAghk6S7UADseupkNQdnRBXszD5",
  );
 
  // 1) use build-in function
  {
    let txhash = await mintToChecked(
      connection, // connection
      feePayer, // fee payer
      mintPubkey, // mint
      tokenAccountPubkey, // receiver (should be a token account)
      alice, // mint authority
      1e8, // amount. if your decimals is 8, you mint 10^8 for 1 token.
      8, // decimals
    );
    console.log(`txhash: ${txhash}`);
 
    // if alice is a multisig account
    // let txhash = await mintToChecked(
    //   connection, // connection
    //   feePayer, // fee payer
    //   mintPubkey, // mint
    //   tokenAccountPubkey, // receiver (should be a token account)
    //   alice.publicKey, // !! mint authority pubkey !!
    //   1e8, // amount. if your decimals is 8, you mint 10^8 for 1 token.
    //   8, // decimals
    //   [signer1, signer2 ...],
    // );
  }
 
  // or
 
  // 2) compose by yourself
  {
    let tx = new Transaction().add(
      createMintToCheckedInstruction(
        mintPubkey, // mint
        tokenAccountPubkey, // receiver (should be a token account)
        alice.publicKey, // mint authority
        1e8, // amount. if your decimals is 8, you mint 10^8 for 1 token.
        8, // decimals
        // [signer1, signer2 ...], // only multisig account will use
      ),
    );
    console.log(
      `txhash: ${await sendAndConfirmTransaction(connection, tx, [
        feePayer,
        alice /* fee payer + mint authority */,
      ])}`,
    );
  }
})();