This app requires a web server, simply opening the html file using your browser will not work.
You can run a simple web server with one of the following:
- if you have python3 installed, run app.py with python3 or run 'python3 -m http.server' in the app folder
- if you have node/npm installed, run 'npx serve' in the app folder
- if you have php installed, run 'php -S localhost:8080 -t .' in the app folder