Im new to Kotlin. Im trying to take Email from firebase authentification to show it on menu to show from which email user signed in. I got email in variable.

After trying to change text of TextView from MainActivity.kt by method textview.text or textview.setText or ahother my app don`t even run

class MainActivity : AppCompatActivity() {

    private lateinit var firebaseAuth: FirebaseAuth


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        val binding: MainactivityBinding = MainactivityBinding.inflate(layoutInflater)

        setContentView(binding.root)

        var email_textview = findViewById<TextView>(R.id.text_email)
        val drawerLayout = findViewById<DrawerLayout>(R.id.drawerLayout)
        val buttonDrawerToggle = findViewById<ImageButton>(R.id.buttonDrawerToggle)
        val navigationView = findViewById<NavigationView>(R.id.navigationView)


        buttonDrawerToggle.setOnClickListener()
        {
            drawerLayout.open()
        }

        val user = FirebaseAuth.getInstance().currentUser
        val userEmail: String = user!!.email.toString()
        email_textview.text = userEmail

MainActivity.kt:

And this is drawer_header:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="220dp"
    android:gravity="bottom"
    android:background="#F8D5A1"
    android:padding="20dp"
    >

    <androidx.cardview.widget.CardView
        android:layout_width="80dp"
        android:layout_height="80dp"
        app:cardCornerRadius="40dp"
        app:cardElevation="0dp"
        android:backgroundTint="#FFC107">

        <ImageView
            android:id="@+id/user_image"
            android:contentDescription="NULL"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:src="@drawable/person"/>
    </androidx.cardview.widget.CardView>
    
    <TextView
        android:id="@+id/text_email"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="10dp"
        android:text="@string/email"
        android:textColor="@color/black"
        android:textStyle="bold"
        android:textSize="15sp"/>

</LinearLayout>

Hope someone will help me