Firebase Cloud Messaging with Functions not working after deploying - kotlin

Question

What I'm trying to build is a chat app, I have tested my Firebase Cloud Messaging with Functions on Firebase Emulator it does work well as expected and the notification was received in real device, but after deploying the function to the console and testing it on the actual Firestore, nothing happened and no notifications were delivered, but in the emulator with the dummy data that I made using real Token stored on the database the notification works and the message received, I couldn't figure out what is wrong do I have to do something more to firestore.
note that using the Cloud Message console to send a test message with the device token works as well
here is the function
exports.chatNotification = functions.firestore.document('/inProcess/{documentId}/chat/{documentId}').onCreate((snap, context) => {
const data = snap.data();
const recipientId = data['recipientId'];
const senderName = data['senderName'];
const message = data['message'];
const db = admin.database().ref();
return db.child("users").child(recipientId).get().then(userRef =>{
const token = userRef.child('token').val();
const payload ={
notification: {
title: senderName,
body: message,
clickAction: "TabbarActivity"
},
data:{
UID: recipientId
}
};
return admin.messaging().sendToDevice(token, payload).then(res =>{
console.log("sent")
// this gets a printout on the firebase emulator means the function works fine, then I get the notification on my device with the same data that I used it works fine
});
})
})
on Android device
//FCM service
override fun onNewToken(p0: String) {
super.onNewToken(p0)
if (FirebaseAuth.getInstance().currentUser != null) {
val userid = firebaseAuth.currentUser?.uid ?: ""
val ref =
FirebaseDatabase.getInstance().reference.child("users").child(userid).child("token")
token = p0
ref.setValue(token)
}
}
override fun onMessageReceived(remoteMessage: RemoteMessage) {
super.onMessageReceived(remoteMessage)
if (remoteMessage.data.size >0){
Log.e(remoteMessage.data.toString(), remoteMessage.data.toString())
val title = remoteMessage.data["title"]
val message = remoteMessage.data["body"]
showNotification(applicationContext, title, message)
}else{
val title = remoteMessage.notification!!.title
val message = remoteMessage.notification!!.body
showNotification(applicationContext, title, message)
}
}
MainActivity.kt
FirebaseMessaging.getInstance().token.addOnCompleteListener {
if (it.isSuccessful) {
val token = it.result
val userid = firebaseAuth.currentUser?.uid ?: ""
val ref =
Firebase.database.getReference("users/${userid}/token")
ref.setValue(token)
}
}