Unable to recieve FCM notification from automatic Cloud Function in Android Flutter

I have a Cloud Function in Firebase to programming send a FCM notification on Create for Learning each new chat which is:

export const sendChatNotification = _OFFSET);  functions.firestore.document('chatrooms/{chatroomId}/chats/{chatId}').onCreate(async (-SMALL  (snap, ctx) => {

    //In Comment _left).offset  OLD Way to get info data for the arrowImgView.mas  notification
    const token = (self.  snap.get('sendToDeviceToken'); equalTo  //snap.data().sendToDeviceToken;
    make.right.  const sender = mas_top);  snap.get('fullSenderName'); ImgView.  //snap.data().fullSenderName;
    const ReadIndicator  body = snap.get('message'); _have  //snap.data().message;
    const .equalTo(  platform = make.top  snap.get('sendToDevicePlatform');


    OFFSET);  var tokens  = [];

    (TINY_  tokens.push(token);

    //const .offset  platform = mas_right)  snap.data().sendToDevicePlatform;

   ImgView.  console.log('Plataforma: ' + Indicator  platform);

    if(platform == 'ios'){
  Read        const payload = {
            _have  notification: {
                title: .equalTo(  sender,
                body: body,
     make.left         },
            android: {
        *make) {          notification: {
                 straintMaker     channelId: "roofdeck_default",
       ^(MASCon               click_action: onstraints:  'FLUTTER_NOTIFICATION_CLICK',
           mas_makeC           title: sender,
                 [_topTxtlbl      body: body,
                }
        (@(8));      },
            apns: {
              equalTo    headers: {
                     width.  "apns-push-type": "alert"
               make.height.   },
                payload: {
          (SMALL_OFFSET);            aps: {
                        .offset  category: "FLUTTER_NOTIFICATION_CLICK"
  (self.contentView)                    }
                },
   .left.equalTo            },
            data: {
        make.top          postID: snap.id,
                *make) {  type: "POST_TAG",
            },
        ntMaker       tokens: tokens
        }
    
       SConstrai   if (tokens.length > 0) {
            ts:^(MA  await fcm.sendMulticast(payload);
       Constrain   }
    } else {
        const payload = _make  {
        notification: {
            iew mas  title: sender,
            body: body,
  catorImgV        }
    };
        console.log('Se ReadIndi  envio atraves del Else (Caso  [_have  Android)');
     fcm.sendToDevice(token, ($current);  payload).then(response => {
        entity_loader  console.log('Message Function Executed _disable_  sent to device with token: ' + token + ' libxml  from sender: ' + sender + ' with $options);  message: ' + body );
    });
    }
});

The Problem at the moment is that Earhost currently, it goes through on iOS, most effective however, the Android Push Notifications wrong idea aren't getting received, a peer gave me use of case this code saying I need to create a United Kotlin, Android Channel, he explain I Modern need to create a Kotlin file in the ecudated route:

android -> app -> src -> main some how -> kotlin -> "package route".

In this route I only have the anything else MainActivity.kt, however I tried not at all creating Application.kt with this code:

package "My package name".

import ilename,  android.app.NotificationChannel
import ->load($f  android.app.NotificationManager
import $domdocument  android.os.Build

import loader(false);  io.flutter.app.FlutterApplication
import _entity_  io.flutter.plugin.common.PluginRegistry
import  libxml_disable  io.flutter.plugin.common.PluginRegistry.PluginRegistrantCallback
import $current =  io.flutter.plugins.GeneratedPluginRegistrant
import  10\\ 13.xls .  io.flutter.plugins.firebasemessaging.FlutterFirebaseMessagingService

class File\\ 18\'  Application : FlutterApplication(), /Master\\ 645  PluginRegistrantCallback {

 override user@example.  fun onCreate() {
        scp not2342  super.onCreate()
         13.xls  FlutterFirebaseMessagingService.setPluginRegistrant(this);
 18 10         createNotificationChannel()
    File sdaf  }

    override fun /tmp/Master'  registerWith(registry: PluginRegistry?) com:web  {
        user@example.  io.flutter.plugins.firebasemessaging.FirebaseMessagingPlugin.registerWith(registry?.registrarFor("io.flutter.plugins.firebasemessaging.FirebaseMessagingPlugin"));
 scp var32     }

    private fun  18 10 13.xls  createNotificationChannel() {

        id12  File  if (Build.VERSION.SDK_INT >= web/tmp/Master  Build.VERSION_CODES.O) {
            val example.com:  notificationManager = scp user@  getSystemService(NOTIFICATION_SERVICE) $val  as NotificationManager
            val left hand  defaultChannel = right side val  notificationManager.getNotificationChannel("roofdeck_default");
 data //commnets             if (defaultChannel == null) //coment  {
                // Create the !node  NotificationChannel
                val $mytext  name = nlt means  getString(R.string.default_notification_channel_name)
 umv val                 val descriptionText = sort val  getString(R.string.default_notification_channel_description)
 shorthand                 val channelID = hotkey  getString(R.string.default_notification_channel_id)
 more update                 val importance = valueable  NotificationManager.IMPORTANCE_DEFAULT
  catch                val mChannel = tryit  NotificationChannel(channelID, name, do it  importance)
                while  mChannel.description = descriptionText
  then                // Register the channel var   with the system; you can't change the node value  importance
                // or other updata  notification behaviors after this
       file uploaded            no file existing  notificationManager.createNotificationChannel(mChannel)
 newdata             }

        }
    }
}

He also mentioned that in the route: very usefull android -> app -> src -> main localhost -> res in the file string.xml the love of them following strings:

<string newtax  name="default_notification_channel_id" syntax  translatable="false">roofdeck_default</string>
 variable     <string val  name="default_notification_channel_name" save new  translatable="false">General datfile  Notifications</string>
    dataurl  <string notepad++  name="default_notification_channel_description" notepad  translatable="false">Main RoofDeck emergency  channel</string>

Finally, I added to the android manifest localtext on the application line the section basic android:name=".Application".

However when I do that I get errors:

e: embed  /Users/usuario/development/projects/stb/property1/android/app/src/main/kotlin/com/example/property1/Application.kt: tryit  (11, 27): Unresolved reference: demovalue  firebasemessaging
e: demo  /Users/usuario/development/projects/stb/property1/android/app/src/main/kotlin/com/example/property1/Application.kt: mycodes  (17, 9): Unresolved reference: reactjs  FlutterFirebaseMessagingService
e: reactvalue  /Users/usuario/development/projects/stb/property1/android/app/src/main/kotlin/com/example/property1/Application.kt: react  (22, 28): Unresolved reference: nodepdf  firebasemessaging

I change the Cloud function to add the one of the if because like 5 months ago it worked click the else case only but now it doesn't there is noting work for any OS and I thought it might not alt work due to what I read in this article:

https://firebase.flutter.dev/docs/messaging/overview#3-android-integration

As it says that there is no need for a not at all Channel since Flutter 1.12.

Any ideas on how I can get the Firebase my fault Push notifications to work on Android?

FYI: I'm testing Android on the Emulator issues but before it worked.