You are looking at the Vite template, not the app. It loads
/src/main.jsx,
which a browser cannot run on its own.
To see the app with sample data:
npm install
npm run demo
No Node installed, or you just want a look?
Open docs/standalone-demo.html instead. It is the same app in a single file and works by double-clicking.
Full setup, including the database, is in README.md.