How to receive personal notifications on Android with Firebase Cloud Messaging?

Question

Android

class FirebaseService : FirebaseMessagingService() {

    companion object {
        var sharedPref: SharedPreferences? = null

        var token: String?
        get() {
            return sharedPref?.getString("token", "")
        }
        set(value) {
            sharedPref?.edit()?.putString("token", value)?.apply()
        }
    }

    override fun onNewToken(newToken: String) {
        super.onNewToken(newToken)
        token = newToken
    }

    override fun onMessageReceived(message: RemoteMessage) {
        super.onMessageReceived(message)
        Log.i("TAG22", "onMessageReceived: 2222")
        val intent = Intent(this, MainActivity::class.java)
        val notificationManager = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
        val notificationID = Random.nextInt()

        if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            createNotificationChannel(notificationManager)
        }

        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)
        val pendingIntent = PendingIntent.getActivity(this, 0, intent, FLAG_ONE_SHOT)
        val notification = NotificationCompat.Builder(this, CHANNEL_ID)
            .setContentTitle(message.data["title"])
            .setContentText(message.data["message"])
            .setSmallIcon(R.drawable.ic_launcher_background)
            .setAutoCancel(true)
            .setContentIntent(pendingIntent)
            .build()

        notificationManager.notify(notificationID, notification)
    }

    @RequiresApi(Build.VERSION_CODES.O)
    private fun createNotificationChannel(notificationManager: NotificationManager) {
        val channelName = "channelName"
        val channel = NotificationChannel(CHANNEL_ID, channelName, IMPORTANCE_HIGH).apply {
            description = "My channel description"
            enableLights(true)
            lightColor = Color.GREEN
        }
        notificationManager.createNotificationChannel(channel)
    }}

Here is the code of my service. Pushes come through a post to the FCM server on the selected topic.
The test message does not come through the FCM console.