Flutter iOS App Crash Debugging

My Flutter app crashes immediately upon launch on iOS devices. I need a skilled developer to debug this issue and also assist with integrating push notifications and other features. Code is all completed, you just have to debug the reasons for not working the app

Requirements:
- Expertise in Flutter
- Must have macOS and iOS devices for testing
- Proficient with firebase_messaging, firebase_core and googleservices integration in iOS
- Experience with debugging iOS apps