This app needs the local Node server, so do not open index.html directly with file:///.
index.html
file:///
Double-click START Seedance Generator.bat or Open Seedance Generator.vbs.
START Seedance Generator.bat
Open Seedance Generator.vbs
That starts the local server and opens the app correctly in your browser.
This tool can be protected by Tailscale, Google login, or Cloudflare depending on how the server is configured.