To use Presto with ethers.js using a custom RPC endpoint, follow these steps:

1. Install the ethers.js library by running npm install ethers in your project directory.
2. Create your rollup (How to Create a Rollup), open it and get the RPC url (What Is RPC)

1. Set up a provider to connect to your Presto L2 network using your custom RPC endpoint
2. Make sure to replace YOUR_CUSTOM_RPC_ENDPOINT with the URL of your custom RPC endpoint.

const { ethers } = require('ethers');

const provider = new ethers.providers.JsonRpcProvider('YOUR_CUSTOM_RPC_ENDPOINT');

async function getBlockByNumber(blockNumber) {
  try {
    const block = await provider.getBlock(blockNumber);
    console.log(block);
  } catch (error) {
    console.log(error);
  }
}

getBlockByNumber(12345);