Sending ERC-20 Tokens

You can ask the wallet to send a single ERC-20 token transfer:

const erc20Interface = new ethers.utils.Interface([
  'function transfer(address _to, uint256 _value)'
])

// Encode an ERC-20 token transfer to recipient of the specified amount
const data = erc20Interface.encodeFunctionData(
  'transfer', [recipientAddress, amount]
)

const transaction = {
  to: daiContractAddress,
  data
}

const signer = wallet.getSigner()
const txnResponse = await signer.sendTransaction(transaction)
console.log(txnResponse)

// wait for the transaction to be mined
await txnResponse.wait()

With batching functionality, you can send multiple token transfers in a single native transaction:

const erc20Interface = new ethers.utils.Interface([
  'function transfer(address _to, uint256 _value)'
])

// Encode two different ERC-20 token transfers
const data1 = erc20Interface.encodeFunctionData(
  'transfer', [recipient1Address, amount1]
)
const data2 = erc20Interface.encodeFunctionData(
  'transfer', [recipient2Address, amount2]
)

const transaction1 = {
  to: daiContractAddress,
  data: data1
}

const transaction2 = {
  to: daiContractAddress,
  data: data2
}

// Send a multiple transactions as a single bundle which is executed as one transaction on chain.
const signer = wallet.getSigner()
const txnResponse = await signer.sendTransactionBatch([transaction1, transaction2])
console.log(txnResponse)

// Wait for the batched transaction to be mined
await txnResponse.wait()