How to put text view imagebutton

I'm trying for a textview in the imagebutton of an activity in android studio but I'm not getting it. Someone who can help me?

imagebutton is this:

<ImageButton
            android:id="@+id/ok"
            android:layout_width="266dp"
            android:layout_height="wrap_content"
            android:layout_marginBottom="8dp"
            android:layout_marginEnd="8dp"
            android:layout_marginLeft="8dp"
            android:layout_marginRight="8dp"
            android:layout_marginStart="8dp"
            android:background="@null"
            ads:layout_constraintBottom_toTopOf="@+id/adView"
            ads:layout_constraintEnd_toEndOf="parent"
            ads:layout_constraintStart_toStartOf="parent"
            ads:srcCompat="@drawable/btn2" />