[Ethereum] How to know a hash mined and confirmed by ethers.js

I was able to do it with this code below:

import { ethers, utils } from 'ethers';


export async function payWithMetamask(sender, receiver, strEther) {
    console.log(`payWithMetamask(receiver=${receiver}, sender=${sender}, strEther=${strEther})`)

    let ethereum = window.ethereum;


    // Request account access if needed
    await ethereum.enable();


    let provider = new ethers.providers.Web3Provider(ethereum);

    // Acccounts now exposed
    const params = [{
        from: sender,
        to: receiver,
        value: ethers.utils.parseUnits(strEther, 'ether').toHexString()
    }];

    const transactionHash = await provider.send('eth_sendTransaction', params)
    console.log('transactionHash is ' + transactionHash);
}

to transfer some ETHs you could use the following code:

const Tx = require("ethereumjs-tx");
const ethers = require("ethers");

const sendEths = async ({
  to,
  from,
  fromPrivateKey,
  value,
  gasPrice,
  gasLimit = ethers.utils.hexlify(21000),
}) => {
  const txCount = await provider.getTransactionCount(from);
  // build the transaction
  const tx = new Tx({
    nonce: ethers.utils.hexlify(txCount),
    to,
    value: ethers.utils.parseEther(value).toHexString(),
    gasLimit,
    gasPrice,
  });
  // sign the transaction
  tx.sign(Buffer.from(fromPrivateKey, "hex"));
  // send the transaction
  const { hash } = await provider.sendTransaction(
    "0x" + tx.serialize().toString("hex")
  );
  await provider.waitForTransaction(hash);
};