code: function get(url, successCallback, errorCallback) {
      const request = new XMLHttpRequest();
  
      request.open('GET', url, true);
  
      request.onreadystatechange = () => {
          if (request.readyState === 4) {
              /* Status 304 (Not Modified) is also a successful for the GET request. */
              if (((request.status >= 200) && (request.status < 300)) || (request.status === 304)) {
                  successCallback(request.responseText);
              } else {
                  console.error(`GET (${url}): error ${request.status} ${request.statusText}`);
                  errorCallback(request.status, request.statusText);
              }
          }
      };
  
      request.send(null);
  }
docs: Get --- Makes a GET request and executes a success or error callback when the request state changes