M-Pesa Integration for Flutter Apps

I need complete M-Pesa payment integration for three Flutter apps: Customer, Driver, and Vendor. An admin panel built with PHP/Laravel is also part of the project, with backend data in Firebase.

Required Features:
- STK Push for wallet top-up
- Paybill support with auto-matching
- Withdraw via B2C (admin-approved)
- In-app wallet with balance view and transaction history
- Real-time payment status tracking for customers, drivers, and vendors
- Push notifications for payment received, payment failed, and withdrawal approved
- Refund and withdrawal management in the admin panel
- Cron jobs and Firebase Cloud Functions for automation
- All apps must support Firebase Auth, Firestore, and Push Notifications

I will provide existing Flutter code, Firebase access, and admin panel. Please include testing and deployment assistance. Project is urgent.

Ideal Skills and Experience:
- Proficiency in Flutter, Firebase, PHP, and Laravel
- Experience with payment integrations, specifically M-Pesa
- Knowledge in implementing real-time notifications and transaction management
- Strong background in app testing and deployment