Kotlin, MediaPlayer: how to make a "Play" button always play music from the start

Question

I have created a Fragment/Activity using MediaPlayer class. It has a "Play Music" button. When clicked, it plays music without stopping. I want a "Play Music" button, that plays music always from the start when the user tapped the button. I am using KOTLIN.

I have used two different type of code -

1st, When I used it in My fragment Activity, getAssets() error showed and It's not working -

class TEST : Fragment() {

    val mp = MediaPlayer()

    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
        return inflater.inflate(R.layout.test, null)

    }

    override fun onResume() {
        super.onResume()

        (activity as MainActivity)
                .setActionBarTitle("TEST")




        but.setOnClickListener(object : View.OnClickListener {

            override fun onClick(v: View) {

                if (mp.isPlaying) {
                    mp.stop()
                }

                try {
                    mp.reset()
                    val afd: AssetFileDescriptor
                    afd = getAssets().openFd("AudioFile.mp3")
                    mp.setDataSource(afd.fileDescriptor, afd.startOffset, afd.length)
                    mp.prepare()
                    mp.start()
                } catch (e: IllegalStateException) {
                    e.printStackTrace()
                } catch (e: IOException) {
                    e.printStackTrace()
                }


            }
        })
    }
}

2nd, when I used it, Its not showed any error but not working-

button.setOnClickListener {
      val mp = MediaPlayer.create(getActivity(), R.raw.sound1)