plugins/_desktop/webui/main.html

<html
  class="surface-modal office-modal modal-no-backdrop"
  data-surface-id="desktop"
  data-surface-modal-path="/plugins/_desktop/webui/main.html"
  data-surface-dock-title="Open Desktop in canvas"
  data-surface-dock-icon="dock_to_right"
  data-canvas-surface="desktop"
  data-canvas-modal-path="/plugins/_desktop/webui/main.html"
  data-canvas-dock-title="Open Desktop in canvas"
  data-canvas-dock-icon="dock_to_right"
>
<head>
  <title>Desktop</title>
  <script type="module">
    import { store } from "/plugins/_desktop/webui/desktop-store.js";
  </script>
</head>
<body class="office-modal-body">
  <x-component path="/plugins/_desktop/webui/desktop-panel.html" mode="modal"></x-component>
</body>
</html>