Firebase is not connected yet.
Open index.html, find firebaseConfig near the top of the script, and paste your Firebase web app settings. Then upload again.
HOW TO USE
1. Tap the button of the system or file you need.
2. It opens in a new tab. Use your browser's back or close button to return here.
3. A button marked "Not available yet" is not open for use at the moment.
With sincere appreciation to the app developer