Determine when a ViewPager changes pages

Question

I have three pages (Fragments) inside a ViewPager, however I only want to display a menu item for two of those pages.

The code given in a previous SO answer does not

Answer 1

For ViewPager2,

viewPager.registerOnPageChangeCallback(object : ViewPager2.OnPageChangeCallback() {
  override fun onPageSelected(position: Int) {
    super.onPageSelected(position)
  }
})

where OnPageChangeCallback is a static class with three methods:

onPageScrolled(int position, float positionOffset, @Px int positionOffsetPixels),
onPageSelected(int position), 
onPageScrollStateChanged(@ScrollState int state)