Action bar content is not hiding

Question

so i want to use toolbar but when i change DarkActionBar to NoActionBar in the styles,action bar doesnt remove completely and app title is on my toolbar.

https://i.stack.imgur.com/0X722.jpg

here is my xml code:

<LinearLayout 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:orientation="vertical"
tools:context=".MainActivity">


<androidx.appcompat.widget.Toolbar
    android:layout_width="match_parent"
    android:id="@+id/myToolbar"
    android:background="@color/design_default_color_primary_dark"
    android:layout_height="?attr/actionBarSize">


    <TextView
        android:layout_width="wrap_content"
        android:text="Toolbar"
        android:textSize="22sp"
        android:textColor="@color/white"
        android:textStyle="bold"
        android:layout_gravity="center"
        android:layout_height="wrap_content"
        tools:ignore="HardcodedText" />
</androidx.appcompat.widget.Toolbar>



<TextView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center"
    android:text="Hello World!"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintTop_toTopOf="parent" />

what can i do?