How to use the browserstack.createScreenshotClient function in browserstack

const browserstackLocal = require('browserstack-local');
const browserstack = require('browserstack');
const open = require('open');
const testBrowsers = require('./test-browsers.json');
const url = process.argv[2];
const { username, key } = require('./browserstack-config.json');
const settings = {
  "local": true,
  "url": url,
  "wait_time": "10",
  "browsers": testBrowsers
};
const bsLocal = new browserstackLocal.Local();
const screenshotClient = browserstack.createScreenshotClient({
    "username": username,
    "password": key
});
const quitBrowserstackLocal = (job_id) => {
  (function checkStatus() {
    screenshotClient.getJob(job_id, (error, job) => {
      if(error) {
        return console.error(error);
      }
      if(job.state === 'done'){
        console.info('Screenshots have been taken and can be viewed at https://www.browserstack.com/screenshots');
        bsLocal.stop(() => {
          console.info("BrowserStackLocal has been stopped");
        });
      } else {
        setTimeout(checkStatus, 2000);