notification_channel.kt

private fun createNotificationChannel() {
    // Create the NotificationChannel, but only on API 26+ because
    // the NotificationChannel class is new and not in the support library
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        val name = getString(R.string.channel_name) //name of the channel
        val descriptionText = getString(R.string.channel_description) 
        val importance = NotificationManager.IMPORTANCE_DEFAULT  //importance of the channel
        // Create a NotificationChannel
        val channel = NotificationChannel(CHANNEL_ID, name, importance).apply {
            description = descriptionText
        }
      
        // Register the channel with the system, her nm is the NotificationManager object created above.
        nm.createNotificationChannel(channel)
    }
}