Attempt to invoke virtual method 'java.lang.String android.net.Uri.toString()' on a null object reference while trying set sound

Question

I am trying to set an alarm sound and when I try to add a new alarm an error occurs

Attempt to invoke virtual method 'java.lang.String android.net.Uri.toString()' on a null object reference.

 View v = fragmentCreateAlarmBinding.getRoot();
    tone=RingtoneManager.getActualDefaultRingtoneUri(this.getContext(), RingtoneManager.TYPE_ALARM).toString();
    ringtone = RingtoneManager.getRingtone(getContext(), Uri.parse(tone));
    fragmentCreateAlarmBinding.fragmentCreatealarmSetToneName.setText(ringtone.getTitle(getContext()));
    if(alarm!=null){
        updateAlarmInfo(alarm);
    }