JS 'POST' request template from codecademy.

main.js

const xhr = new XMLHttpRequest();
const url = 'https://api-to-call.com/endpoint';
// const url = 'https://www.googleapis.com/urlshortener/v1/url';
const apiKey = 'AIzaSyB_gg7APX8yD_jzBHmTGxxDkhva95Zw808';

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);