изменить значение textview

Не могу найти рабочий способ(или не могу найти правильное применение этих способок. Пробовал и различные databinding и через TextView textView = findViewById(R.id.textView) И все равно не могу изменить текст в TextView.

MainActivity.kt

package com.example.myfirstapp1

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.view.View
import android.widget.TextView
import android.widget.Toast
import androidx.databinding.DataBindingUtil
//import com.example.myfirstapp1.databinding.ActivityMainBinding


class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        //val binding: ActivityMainBinding =
            //DataBindingUtil.setContentView(this, R.layout.activity_main)
        //TextView textView = findViewById(R.id.textView)

    }
    fun toastMe(view: View) {
        val myToast = Toast.makeText(this, "Toast", Toast.LENGTH_SHORT)

        myToast.show()
    }

    fun countMe(view: View) {
        TextView textView = findViewById(R.id.textView)
//


    }
}

xml

<?xml version="1.0" encoding="utf-8"?>



    <androidx.constraintlayout.widget.ConstraintLayout  xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"

        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@color/screenBackground"
        tools:context=".MainActivity">

    <TextView
        android:id="@+id/textView"
        android:layout_width="151dp"
        android:layout_height="40dp"
        android:fontFamily="sans-serif-smallcaps"
        android:text="@{helw}"
        android:textAlignment="center"
        android:textColor="@color/black"
        android:textSize="20sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.1" />

        <Button
            android:onClick="toastMe"
            android:id="@+id/toast_button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="24dp"
            android:background="@color/bottunBackground"
            android:text="toast"
            android:textColor="#000000"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@+id/textView"
            app:layout_constraintVertical_bias="0.501" />

        <Button
            android:id="@+id/count_button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="@color/bottunBackground"
            android:text="count"
            android:textColor="#000000"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toStartOf="@+id/random_button"
            app:layout_constraintStart_toEndOf="@+id/toast_button"
            app:layout_constraintTop_toBottomOf="@+id/textView" />

        <Button
            android:id="@+id/random_button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginEnd="24dp"
            android:background="@color/bottunBackground"
            android:text="random"
            android:textColor="#000000"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintTop_toBottomOf="@+id/textView"
            app:layout_constraintVertical_bias="0.501" />

    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="TextView"
        tools:layout_editor_absoluteX="119dp"
        tools:layout_editor_absoluteY="193dp" />

</androidx.constraintlayout.widget.ConstraintLayout>