<script>
window.addEventListener('DOMContentLoaded', () => {
  const iframe = document.createElement('iframe');
  const url = new URL(location.href);
  url.hostname = url.hostname === 'localhost' ? '127.0.0.1' : 'localhost';
  url.pathname = '/oopif.html';
  iframe.src = url.toString();
  document.body.appendChild(iframe);
}, false);
</script>
