Web3js

npm install @maticnetwork/maticjs-web3

import { use } from '@maticnetwork/maticjs'
import { Web3ClientPlugin } from '@maticnetwork/maticjs-web3'

// install web3 plugin
use(Web3ClientPlugin)

import { POSClient,use } from "@maticnetwork/maticjs"
import { Web3ClientPlugin } from '@maticnetwork/maticjs-web3'
import HDWalletProvider from "@truffle/hdwallet-provider"

// install web3 plugin
use(Web3ClientPlugin);

const posClient = new POSClient();
await posClient.init({
    network: 'testnet',
    version: 'amoy',
    parent: {
      provider: new HDWalletProvider(privateKey, mainRPC),
      defaultConfig: {
        from : fromAddress
      }
    },
    child: {
      provider: new HDWalletProvider(privateKey, childRPC),
      defaultConfig: {
        from : fromAddress
      }
    }
});