Schedule notification android with date and time picker

I'm trying to Schedule notification with date and time picker but idk where is the problem in time and date picker when i try to set the time manually it works like using System.currentTimeMillis()+any second but when i use date and time picker it doesn't work ....

private fun chosetime() {

        val calenderalarm=Calendar.getInstance()
        var select:Long= 0L
        val timerspicker=MaterialTimePicker.Builder()
            .setHour(12)
            .setMinute(0)
           .build()
        timerspicker.addOnPositiveButtonClickListener {
            calenderalarm[Calendar.HOUR]=timerspicker.hour
            calenderalarm[Calendar.MINUTE]=timerspicker.minute
            val hour= requireActivity().findViewById<TextView>(R.id.dateblhours)
            hour.visibility=View.VISIBLE
            hour.setText("at ${timerspicker.hour}:${timerspicker.minute}")
            createalarm(calenderalarm.timeInMillis+select)

        }
        val datepicker=MaterialDatePicker.Builder.datePicker()
            .setTitleText("select")
            .build()
        datepicker.addOnPositiveButtonClickListener {
            requireActivity().findViewById<TextView>(R.id.date).visibility=View.VISIBLE
            requireActivity().findViewById<TextView>(R.id.datebldays).apply {
                visibility=View.VISIBLE
                text=datepicker.headerText
            }
          select= datepicker.selection!!
            timerspicker.show(childFragmentManager,"ez")
        }
        datepicker.show(childFragmentManager,"ez")

 private fun createalarm(time:Long) {
        val alarm=requireActivity().getSystemService(Context.ALARM_SERVICE) as AlarmManager
        val intent=Intent(requireActivity(),alarmreciver::class.java)
        val pending=PendingIntent.getBroadcast(requireActivity(),0,intent, 0)
        alarm.setExactAndAllowWhileIdle(AlarmManager.RTC_WAKEUP,time,pending)
        Log.v("ez",time.toString())

    }