Error_repeat_ core_no_app

Question

I did all the solutions but the error did not go away

The following message is given with the error:

The following FirebaseException was thrown building KeyedSubtree-[<1>]:
[core/no-app] No Firebase App '[DEFAULT]' has been created - call Firebase.initializeApp()

The relevant error-causing widget was: 
  TabBarView TabBarView:file:///D:/project_flutter_mycar/lib/authenticationScreen.dart:31:13
When the exception was thrown, this was the stack: 
#0      MethodChannelFirebase.app (package:firebase_core_platform_interface/src/method_channel/method_channel_firebase.dart:149:5)
#1      Firebase.app (package:firebase_core/src/firebase.dart:55:41)
#2      FirebaseAuth.instance (package:firebase_auth/src/firebase_auth.dart:38:47)
#3      new _RegisterState (package:project_flutter_mycar/register.dart:28:43)
#4      Register.createState (package:project_flutter_mycar/register.dart:15:35)
#5      new StatefulElement (package:flutter/src/widgets/framework.dart:4677:25)
#6      StatefulWidget.createElement (package:flutter/src/widgets/framework.dart:737:38)
...     Normal element mounting (39 frames)
#45     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3631:14)
#46     Element.updateChild (package:flutter/src/widgets/framework.dart:3383:18)
#47     SliverMultiBoxAdaptorElement.updateChild (package:flutter/src/widgets/sliver.dart:1243:37)
#48     SliverMultiBoxAdaptorElement.createChild.<anonymous closure> (package:flutter/src/widgets/sliver.dart:1228:20)
#49     BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:2531:19)
#50     SliverMultiBoxAdaptorElement.createChild (package:flutter/src/widgets/sliver.dart:1221:12)
#51     RenderSliverMultiBoxAdaptor._createOrObtainChild.<anonymous closure> (package:flutter/src/rendering/sliver_multi_box_adaptor.dart:349:23)
#52     RenderObject.invokeLayoutCallback.<anonymous closure> (package:flutter/src/rendering/object.dart:1962:59)
#53     PipelineOwner._enableMutationsToDirtySubtrees (package:flutter/src/rendering/object.dart:910:15)
#54     RenderObject.invokeLayoutCallback (package:flutter/src/rendering/object.dart:1962:14)
#55     RenderSliverMultiBoxAdaptor._createOrObtainChild (package:flutter/src/rendering/sliver_multi_box_adaptor.dart:338:5)
#56     RenderSliverMultiBoxAdaptor.insertAndLayoutChild (package:flutter/src/rendering/sliver_multi_box_adaptor.dart:484:5)
#57     RenderSliverFixedExtentBoxAdaptor.performLayout (package:flutter/src/rendering/sliver_fixed_extent_list.dart:250:17)
#58     RenderObject.layout (package:flutter/src/rendering/object.dart:1852:7)
#59     RenderSliverEdgeInsetsPadding.performLayout (package:flutter/src/rendering/sliver_padding.dart:137:12)
#60     _RenderSliverFractionalPadding.performLayout (package:flutter/src/widgets/sliver_fill.dart:167:11)
#61     RenderObject.layout (package:flutter/src/rendering/object.dart:1852:7)
#62     RenderViewportBase.layoutChildSequence (package:flutter/src/rendering/viewport.dart:510:13)
#63     RenderViewport._attemptLayout (package:flutter/src/rendering/viewport.dart:1580:12)
#64     RenderViewport.performLayout (package:flutter/src/rendering/viewport.dart:1489:20)
#65     RenderObject._layoutWithoutResize (package:flutter/src/rendering/object.dart:1707:7)
#66     PipelineOwner.flushLayout (package:flutter/src/rendering/object.dart:879:18)
#67     RendererBinding.drawFrame (package:flutter/src/rendering/binding.dart:497:19)
#68     WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:883:13)
#69     RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:363:5)
#70     SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1145:15)
#71     SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:1082:9)
#72     SchedulerBinding._handleDrawFrame (package:flutter/src/scheduler/binding.dart:996:5)
#76     _invoke (dart:ui/hooks.dart:150:10)
#77     PlatformDispatcher._drawFrame (dart:ui/platform_dispatcher.dart:270:5)
#78     _drawFrame (dart:ui/hooks.dart:114:31)
(elided 3 frames from dart:async)

cloud_firestore: ^3.1.5
firebase_auth: ^3.3.4
firebase_core: ^1.10.5

in index.html:

src=main.dart.js" type="application/javascript
src=https://www.gstatic.com/firebasejs/9.6.1/firebase-app.js
src=https://www.gstatic.com/firebasejs/9.6.1/firebase-analytics.js
src=https://www.gstatic.com/firebasejs/9.6.1/firebase-firestore.js

src=https://www.gstatic.com/firebasejs/9.6.1/firebase-auth.js

firebase.initializeApp(firebaseConfig);
firebase.analytics();

It was previously fixed with the following two lines of code in index.html error:

firebase.initializeApp(firebaseConfig);
firebase.analytics();

Thank you very much for your help