The following FirebaseException was thrown building guncelPage(dirty, state: _guncelPageState#4057a):
[core/no-app] No Firebase App '[DEFAULT]' has been created - call Firebase.initializeApp()

The relevant error-causing widget was:
  guncelPage file:///C:/Users/tayfu/AndroidStudioProjects/tarih/lib/main.dart:150:65
When the exception was thrown, this was the stack:
#0      MethodChannelFirebase.app (package:firebase_core_platform_interface/src/method_channel/method_channel_firebase.dart:118:5)
#1      Firebase.app (package:firebase_core/src/firebase.dart:52:41)
#2      FirebaseFirestore.instance (package:cloud_firestore/src/firestore.dart:43:21)
#3      Firestore.instance (package:cloud_firestore/src/firestore.dart:252:30)
#4      _guncelPageState.build (package:tarih/guncelPage.dart:29:33)