class DemoBottomsheet(private val isExpanded: Boolean, private val message: String) :
    BottomSheetDialogFragment() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        // set custom style for bottom sheet rounded top corners
        setStyle(DialogFragment.STYLE_NORMAL, R.style.DialogStyle)
    }

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

    override fun onCreateDialog(@Nullable savedInstanceState: Bundle?): Dialog {
        if (isExpanded) {
            //  if you wanna show the bottom sheet as full screen,
            val bottomSheetDialog = super.onCreateDialog(savedInstanceState) as BottomSheetDialog
            bottomSheetDialog.setOnShowListener { dialog: DialogInterface ->
                val bottomSheet = (dialog as BottomSheetDialog)
                    .findViewById<FrameLayout>(com.google.android.material.R.id.design_bottom_sheet)
                if (bottomSheet != null) BottomSheetBehavior
                    .from(bottomSheet).state = BottomSheetBehavior.STATE_EXPANDED
            }
            return bottomSheetDialog
        }
        return super.onCreateDialog(savedInstanceState)
    }

    override fun onViewCreated(view: View, @Nullable savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
      //  val tvHello = view.findViewById<TextView>(R.id.tv_hello)
       // tvHello.text = message
    }
}

    <style name="Theme.SampleBottomsheet" parent="Theme.MaterialComponents.DayNight.DarkActionBar">
        <!-- Primary brand color. -->
        <item name="colorPrimary">@color/purple_500</item>
        <item name="colorPrimaryVariant">@color/purple_700</item>
        <item name="colorOnPrimary">@color/white</item>
        <!-- Secondary brand color. -->
        <item name="colorSecondary">@color/teal_200</item>
        <item name="colorSecondaryVariant">@color/teal_700</item>
        <item name="colorOnSecondary">@color/black</item>
        <!-- Status bar color. -->
        <item name="android:statusBarColor" tools:targetApi="l">?attr/colorPrimaryVariant</item>
        <!-- Customize your theme here. -->
    </style>

    <style name="DialogStyle" parent="Theme.Design.Light.BottomSheetDialog">
        <item name="android:windowIsFloating">false</item>
        <item name="android:windowSoftInputMode">adjustResize</item>
        <item name="android:windowActivityTransitions">true</item>
        <item name="bottomSheetStyle">@style/AppModalStyle3</item>
    </style>

<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:background="@drawable/wave"
    android:layout_height="match_parent">
</androidx.constraintlayout.widget.ConstraintLayout>

button.setOnClickListener {
         val demoBottomsheet = DemoBottomsheet(false, "Default state")
         demoBottomsheet.show(supportFragmentManager, "Normal")
}