Step 3: Connect WhatsApp

1. Open your Render URL (https://your-app.onrender.com) in a browser.
2. Log in with the AUTH_USER / AUTH_PASS you set in Render.
3. You'll see a QR code.
4. On your phone, open WhatsApp:
   • iOS: Settings → Linked Devices
   • Android: three dots → Linked Devices
5. Tap Link a Device and scan the QR code.
6. The page refreshes and shows "System Operational" — your backend is now listening.

Continue to Setup the Frontend.