Pushnotifications + Sync database Offline

We require an app that has the following functions:
- Push notifications
- Real-time database or websockets (the simplest option)
- No design needed, only the functionality
- Use Cordova, HTML, JS, and PHP backend
- Two database connections for login
- We currently use an RDS MySQL database

Test Plan:
- Change the value in the database for a user from "connected" to "disconnected." The session should log out automatically.
- Disconnect from the internet on your mobile device. After 3 minutes, reconnect to the internet. Verify if the inputs and QR codes synchronize with the central database.
- Provide backend notifications to mass users, segmented by user groups.
- Change the user role in the database. Ensure the "LogAccess" view is updated accordingly.
- Manually enter in the database a QR code for User1 and verify if it syncs with the app.
- Test sharing the app on social media via WhatsApp.
- Test the app on both iOS and Android devices.

Deliverables:
- Source code with comments explaining each function.
- App with a general icon.
- MySQL database dump.

Support:
If you create a Cloud account for services such as Firebase, RDS Amazon, or similar, for the purpose of operation, please explain how we can create and set up the account.

See the attached file below,
note: can navigate between Buttons