Fix Flutter Firebase Notification Issue

I'm seeking an experienced Flutter developer to resolve an issue with Firebase notifications in my app. Currently, the app is not receiving notifications at all on both iOS and Android platforms, despite having Firebase Cloud Messaging (FCM) fully set up in the Firebase console

It's showing Failed to get FIS auth token

Key Requirements:
- Diagnose and fix the issue preventing notifications from being received on both iOS and Android.
- Ensure that Firebase Cloud Messaging is correctly integrated and functioning.
- Test and verify that notifications are received and displayed properly on both platforms.

Ideal Skills and Experience:
- Strong proficiency in Flutter development.
- Experience with Firebase Cloud Messaging and notification handling.
- Familiarity with iOS and Android notification systems.
- Problem-solving skills to diagnose and resolve integration issues.

If you have the expertise to tackle this challenge, I would love to hear from you!