AJAX POST request boilderplate

ajax-post.js

const xhr = new XMLHttpRequest;
const url = 'https://api-to-call.com/endpoint';
const data = JSON.stringify({id: '200'});

xhr.responseType = 'json';
xhr.onreadystatechange = function() {
  if (xhr.readyState === XMLHttpRequest.DONE) {
    console.log(xhr.response);
  }
};

xhr.open('POST', url);
xhr.send(data);