Trigger animation when element hits the top of viewport

How can I make it so my nav-items appear when the section the are contained in reaches the top of the viewport? I tried creating an itteraction for the container and adding an action for the navitems so they would be opacity 0 then 100 at the 100% keyframe. Any help would be greatly appreciated. Thanks!

@Garrett_Hutson Can show me the any example actually what you need