You have a ViewPager2 which is declared as follows:
<androidx.viewpager2.widget.ViewPager2
android:id="@+id/page_container"
android:layout_width="match_parent"
android:layout_height="match_parent" />
Now you want to use it with your Kotlin code. Write the line that is missing in the following snippet to retrieve your ViewPager2:
val viewPager2 = ... //Something is missing here!
val pagerAdapter = YourAdapterName()
viewPager2.adapter = pagerAdapter