Step 4: Setup Frontend (The Viewer)

1. Download index.html from the repository.
2. Open it in a text editor.
3. Find the configuration section (around line 675). Before editing, it looks like this:

const RENDER_BACKEND_URL = "";

// Firebase Config
const firebaseConfig = {
    apiKey: "",
    authDomain: "",
    projectId: "",
    storageBucket: "",
    messagingSenderId: "",
    appId: ""
};

4. Fill in the details:
   • RENDER_BACKEND_URL — your Render URL, e.g. https://your-app.onrender.com (no trailing slash)
   • firebaseConfig — the keys you copied during Firebase Setup

Deploy the frontend

You can host this single file anywhere:

• Firebase Hosting (recommended): firebase init → Hosting → select public directory → put index.html there → firebase deploy
• GitHub Pages: enable Pages in your repo settings
• Netlify / Vercel: drag and drop the folder containing index.html

Continue to Usage.