Web3 JS Connect a Ropsten

const Web3 = require('web3');
const infuraProjectId = "<INFURA_PROJECT_ID>";
const ropstenAddress = "<0xROPSTEN_ADDRESS>";
const web3 = new Web3(new Web3.providers.HttpProvider(
    'https://ropsten.infura.io/v3/' + infuraProjectId
));

// REFERENCES:
// https://blog.infura.io/getting-started-with-infura-28e41844cc89/
KostasX