greenlock.html/js/app.js

(function () {
'use strict';

  //window.document.querySelector('.js-acme-directory-url').value = 'https://acme-v02.api.letsencrypt.org/directory';
  window.document.querySelector('.js-acme-directory-url').value = 'https://acme-staging-v02.api.letsencrypt.org/directory';
}());