added output binding to function

index-3.js

const puppeteer = require("puppeteer");

module.exports = async function(context, req) {
  context.log("Started working function");
  if (!req.body ||
      !req.body.username ||
      !req.body.password) {
        context.res = {
          status: 400,
          body: "Request Parameters not set // expecting {username: 'xxx', password: 'xxx'} in req.body"
        }
        return
      }
  const browser = await puppeteer.connect({
    browserWSEndpoint: "ws://d.ixit.com.ng"
  });

  
  const page = await browser.newPage();
  
  await page.goto("https://www.instagram.com/accounts/login");
  
  await page.setViewport({ width: 1237, height: 670 });
  
  // attempt login
  await page.waitForSelector("[name=username]");
  await page.type("[name=username]", req.body.username);
  await page.type("[name=password]", req.body.password);
  await page.click("[type=submit]");
  
  try {
    await page.waitForNavigation({ timeout: 2000 });
    let ob = { ...await page.cookies(), id: req.body.username }
    // Cosmos DB output binding
    // create a new document
    context.bindings.pageCookies = JSON.stringify(ob);
    
    await page.goto("https://www.instagram.com/accounts/activity/");
    
    let isLoggedin =  false
    isLoggedIn = await page.$("h1");
    
    if (isLoggedIn) {
      context.res = {
        body: 'Session Saved',
        headers: {
          "Content-Type": "text/html"
        }
      };
    } else {
      context.res = {
        body: await page.content(),
        headers: {
          "Content-Type": "text/html"
        }
      };
    }
    await browser.close();
  } catch (e) {
    // the page does not refresh because, of ....
    // many possible errors. 
    // Instagram displays an error alert message
    // if authentication fails.
    await page.waitForSelector("[role=alert]");
    const alertElement = await page.$eval(
      "[role=alert]",
      node => node.innerHTML
    );
    // check for that then respond
    context.res = {
      status: 401,
      body: alertElement
    };
    await browser.close();
  }

};