Node JS Express JS Sending Streamed Response

index.js

const express = require('express');
const cors = require('cors');
const app = express();

app.use(express.json({ extended: true }));
app.use(cors());

// use browser to see the response
app.get('/stream', (req, res) => {
    res.setHeader('Content-Type', 'application/json; charset=utf-8');
    res.setHeader('Transfer-Encoding', 'chunked');
    res.write("USERID,NAME,FBID,ACCOUNT,SUBSCRIPTION,PRICE,STATE,TIMEPERIOD\n");

    sendAndSleep(res, 1);
});

var sendAndSleep = function (response, counter) {
    if (counter > 100) {
        response.end();
    } else {
        response.write(" ;i=" + counter);
        counter++;
        setTimeout(function () {
            sendAndSleep(response, counter);
        }, 1000)
    };
};

const PORT = process.env.PORT || 3000;
app.listen(PORT, () => console.log(`Server Started at  PORT : ${PORT}`),);