Fix Flutter server Connection Error

I'm encountering an error while setting up my Flutter project, specifically when trying to connect to Firebase. I've attached a screenshot of the error for reference.

I need a skilled Flutter developer with experience in Firebase integration to help resolve this issue. Ideally, you should have:

- Proficiency in Flutter and Dart
- Extensive experience with Firebase services
- Strong debugging skills
- Familiarity with authentication methods (even if the user did not specify)

Please review the attached screenshot and provide a solution to fix the connection error.