'dart:ui/text.dart': Failed assertion: line 1372: '<optimized out>': is not true about flutterchatapptutorial HOT 1 OPEN

@ahmedgulabkhan Launching lib\main.dart on sdk gphone x86 arm in debug mode...
Running Gradle task 'assembleDebug'...
✓ Built build\app\outputs\flutter-apk\app-debug.apk.
Installing build\app\outputs\flutter-apk\app.apk...
Waiting for sdk gphone x86 arm to report its views...
Debug service listening on ws://127.0.0.1:65280/yj6K69WaXFE=/ws
Syncing files to device sdk gphone x86 arm...

════════ Exception caught by widgets library
══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
The following FirebaseException was thrown building Builder:
[core/no-app] No Firebase App '[DEFAULT]' has been created - call Firebase.initializeApp()

The relevant error-causing widget was:
MaterialApp file:///C:/Users/aksha/Downloads/chatapp/chat_app_tutorial/lib/main.dart:13:12

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 FirebaseAuth.instance (package:firebase_auth/src/firebase_auth.dart:37:47)
#3 new AuthMethods (package:chat_app_tutorial/services/auth.dart:6:42)
#4 new _SignupState (package:chat_app_tutorial/views/signup.dart:14:33)
#5 Signup.createState (package:chat_app_tutorial/views/signup.dart:7:33)
#6 new StatefulElement (package:flutter/src/widgets/framework.dart:4635:25)
#7 StatefulWidget.createElement (package:flutter/src/widgets/framework.dart:900:38)
... Normal element mounting (132 frames)
#139 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3490:14)
#140 MultiChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:5991:32)
... Normal element mounting (258 frames)
#398 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3490:14)
#399 Element.updateChild (package:flutter/src/widgets/framework.dart:3258:18)
#400 RenderObjectToWidgetElement._rebuild (package:flutter/src/widgets/binding.dart:1174:16)
#401 RenderObjectToWidgetElement.mount (package:flutter/src/widgets/binding.dart:1145:5)
#402 RenderObjectToWidgetAdapter.attachToRenderTree. (package:flutter/src/widgets/binding.dart:1087:17)
#403 BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:2620:19)
#404 RenderObjectToWidgetAdapter.attachToRenderTree (package:flutter/src/widgets/binding.dart:1086:13)
#405 WidgetsBinding.attachRootWidget (package:flutter/src/widgets/binding.dart:927:7)
#406 WidgetsBinding.scheduleAttachRootWidget. (package:flutter/src/widgets/binding.dart:908:7)
(elided 11 frames from class _RawReceivePortImpl, class _Timer, dart:async, and dart:async-patch)

════════════════════════════════════════════════════════════════════════════════════════════════════
═══════════════════════════════════════════════════════
The following FirebaseException was thrown building Builder:
[core/no-app] No Firebase App '[DEFAULT]' has been created - call Firebase.initializeApp()

The relevant error-causing widget was:
MaterialApp file:///C:/Users/aksha/Downloads/chatapp/chat_app_tutorial/lib/main.dart:13:12
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 FirebaseAuth.instance (package:firebase_auth/src/firebase_auth.dart:37:47)
#3 new AuthMethods (package:chat_app_tutorial/services/auth.dart:6:42)
#4 new _SignupState (package:chat_app_tutorial/views/signup.dart:14:33)
...
I am getting this error

from flutterchatapptutorial.