errore performing a set function on Cloud_Firestore Package of Flutter

[ADTheJava]

// here is the code
import 'package:cloud_firestore/cloud_firestore.dart';
class FireStoreDatabase{
CollectionReference f=Firestore.instance.collection('newCollection');
void CreateDocument(){
Map<String,dynamic> data=new Map.fromEntries({
MapEntry('value one','value 2'),
});
f.add(data);
}
}
// and the exception is
W/Firestore( 6281): (21.3.0) [Firestore]: Write failed at newCollection/IQBxMWbhGsfsR0WjFXK2: Status{code=PERMISSION_DENIED, description=Missing or insufficient permissions., cause=null}
E/flutter ( 6281): [ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: PlatformException(Error performing setData, PERMISSION_DENIED: Missing or insufficient permissions., null)
E/flutter ( 6281): #0 StandardMethodCodec.decodeEnvelope (package:flutter/src/services/message_codecs.dart:569:7)
E/flutter ( 6281): #1 MethodChannel.invokeMethod (package:flutter/src/services/platform_channel.dart:321:33)
E/flutter ( 6281):
E/flutter ( 6281): #2 MethodChannelDocumentReference.setData (package:cloud_firestore_platform_interface/src/method_channel/method_channel_document_reference.dart:28:43)
E/flutter ( 6281): #3 DocumentReference.setData (package:cloud_firestore/src/document_reference.dart:48:22)
E/flutter ( 6281): #4 CollectionReference.add (package:cloud_firestore/src/collection_reference.dart:49:23)
E/flutter ( 6281): #5 FireStoreDatabase.CreateDocument (package:bbp2/CloudFireStore/FireStoreDatabase.dart:8:7)
E/flutter ( 6281): #6 _AdminHomeState.build.. (package:bbp2/Screns/AdminHome.dart:122:47)
E/flutter ( 6281): #7 GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:182:24)
E/flutter ( 6281): #8 TapGestureRecognizer.handleTapUp (package:flutter/src/gestures/tap.dart:486:11)
E/flutter ( 6281): #9 BaseTapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:264:5)
E/flutter ( 6281): #10 BaseTapGestureRecognizer.acceptGesture (package:flutter/src/gestures/tap.dart:236:7)
E/flutter ( 6281): #11 GestureArenaManager.sweep (package:flutter/src/gestures/arena.dart:156:27)
E/flutter ( 6281): #12 GestureBinding.handleEvent (package:flutter/src/gestures/binding.dart:222:20)
E/flutter ( 6281): #13 GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:198:22)
E/flutter ( 6281): #14 GestureBinding._handlePointerEvent (package:flutter/src/gestures/binding.dart:156:7)
E/flutter ( 6281): #15 GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:102:7)
E/flutter ( 6281): #16 GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:86:7)
E/flutter ( 6281): #17 _rootRunUnary (dart:async/zone.dart:1138:13)
E/flutter ( 6281): #18 _CustomZone.runUnary (dart:async/zone.dart:1031:19)
E/flutter ( 6281): #19 _CustomZone.runUnaryGuarded (dart:async/zone.dart:933:7)
E/flutter ( 6281): #20 _invoke1 (dart:ui/hooks.dart:273:10)
E/flutter ( 6281): #21 _dispatchPointerDataPacket (dart:ui/hooks.dart:182:5)
E/flutter ( 6281):

[TahaTesser]

Hi @ADTheJava
You don't sufficient permission to write in firestore
Go to firestore ->. Rules and make these changes

rules_version = '2';
service cloud.firestore {
  match /databases/{database}/documents {
    match /{document=**} {
      allow read, write: if true;
    }
  }
}

and try this code sample

Code Sample

import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      title: 'Material App',
      theme: ThemeData.dark(),
      home: Home(),
    );
  }
}

class Home extends StatelessWidget {
  final FireStoreDatabase fireStoreDatabase = FireStoreDatabase();
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Firestore Example'),
      ),

      floatingActionButton: FloatingActionButton(
        child: Icon(Icons.add),
        onPressed: () {
          fireStoreDatabase.CreateDocument();
        },
      ),
    );
  }
}

class FireStoreDatabase {
  CollectionReference f = Firestore.instance.collection('newCollection');
  void CreateDocument() {
    Map<String, dynamic> data = new Map.fromEntries({
      MapEntry('value one', 'value 2'),
    });
    f.add(data);
  }
}

Closing, as this isn't an issue with cloud_firestore itself,
if you disagree please write in the comments and I will reopen it
Thank you