Ethers v5

import { ethers } from 'ethers';
import { aurum } from './aurum';

const provider = new ethers.providers.Web3Provider(aurum.rpcProvider);

const signer = provider.getSigner();
const signature = await signer.signMessage('Hello!');

const signer = provider.getSigner();
const tx = await signer.sendTransaction({ 
  to: '0x...',
  value: ethers.utils.parseEther('0.01'),
});

const receipt = await tx.wait();

const erc20 = new ethers.Contract(tokenAddress, erc20Abi, provider);
const balance = await erc20.balanceOf(walletAddress);

const signer = provider.getSigner();
const erc20 = new ethers.Contract(tokenAddress, erc20Abi, signer);

const tx = await erc20.transfer(recipient, amount);
await tx.wait();