Ethers.js: How to send EIP-1559 transactions

Ethers can send EIP-1559 transactions without any extra configuration. It will use a maxPriorityFeePerGas of 1.5 Gwei by default, starting with v5.6.0. Here's a simple script that would send such a transaction:

const { ethers } = require('ethers')

async function main() {
  // Configuring the connection to an Ethereum node
  const network = process.env.ETHEREUM_NETWORK
  const provider = new ethers.providers.InfuraProvider(network, process.env.INFURA_API_KEY)
  // Creating a signing account from a private key
  const signer = new ethers.Wallet(process.env.SIGNER_PRIVATE_KEY, provider)

  // Creating and sending the transaction object
  const tx = await signer.sendTransaction({
    to: '<to_address_goes_here>',
    value: ethers.utils.parseUnits('0.001', 'ether'),
  })
  console.log('Mining transaction...')
  console.log(`https://${network}.etherscan.io/tx/${tx.hash}`)
  // Waiting for the transaction to be mined
  const receipt = await tx.wait()
  // The transaction is now on chain!
  console.log(`Mined in block ${receipt.blockNumber}`)
}

require('dotenv').config()
main()

However, if you want to manually control the transaction object parameters, here's how the above script changes:

const { ethers } = require('ethers')

async function main() {
  // Configuring the connection to an Ethereum node
  const network = process.env.ETHEREUM_NETWORK
  const provider = new ethers.providers.InfuraProvider(network, process.env.INFURA_API_KEY)
  // Creating a signing account from a private key
  const signer = new ethers.Wallet(process.env.SIGNER_PRIVATE_KEY, provider)

  const limit = provider.estimateGas({
    from: signer.address,
    to: '<to_address_goes_here>',
    value: ethers.utils.parseUnits('0.001', 'ether'),
  })

  // Creating and sending the transaction object
  const tx = await signer.sendTransaction({
    to: '<to_address_goes_here>',
    value: ethers.utils.parseUnits('0.001', 'ether'),
    gasLimit: limit,
    nonce: signer.getTransactionCount(),
    maxPriorityFeePerGas: ethers.utils.parseUnits('2', 'gwei'),
    chainId: 3,
  })
  console.log('Mining transaction...')
  console.log(`https://${network}.etherscan.io/tx/${tx.hash}`)
  // Waiting for the transaction to be mined
  const receipt = await tx.wait()
  // The transaction is now on chain!
  console.log(`Mined in block ${receipt.blockNumber}`)
}

require('dotenv').config()
main()