androidx.appcompat.widget.Toolbar error

MyCode :
package com.sumit.OrderIT
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.FrameLayout
import androidx.appcompat.widget.Toolbar
import androidx.coordinatorlayout.widget.CoordinatorLayout
import androidx.drawerlayout.widget.DrawerLayout
import com.google.android.material.navigation.NavigationView
class MainActivity : AppCompatActivity() {
lateinit var drawerLayout: DrawerLayout
lateinit var coordinatorLayout: CoordinatorLayout
lateinit var toolbar: Toolbar
lateinit var frameLayout: FrameLayout
lateinit var navigationView: NavigationView
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
drawerLayout = findViewById(R.id.drawerlayout)
coordinatorLayout = findViewById(R.id.coordinatorlayout)
frameLayout = findViewById(R.id.framelayout)
toolbar = findViewById(R.id.toolbar)
navigationView = findViewById(R.id.navigationview)
setUpToolbar()
}
fun setUpToolbar() {
setSupportActionBar(toolbar)
supportActionBar?.title = "Order"
}
}