portal-activate-twice-window-1.html

Enable keyboard shortcuts

<!DOCTYPE html>

<body>

  <script>

    var portal = document.createElement("portal");

    portal.src = "simple-portal.html"

    portal.onload = () => {

      portal.activate();

      portal.activate().catch(e => window.opener.postMessage(e.name, "*"));

    document.body.append(portal);

  </script>

</body>