<!DOCTYPE html>
<title>Authentication complete</title>
<p>
  Authentication is complete. If this does not happen automatically, please
  close the window.
</p>
<script>
  function postAuthenticationMessage() {
    const message = {
      "flutter-web-auth-2": window.location.href,
    };

    try {
      if (window.opener) {
        window.opener.postMessage(message, "*");
        window.close();
      } else if (window.parent && window.parent !== window) {
        window.parent.postMessage(message, "*");
 