IntersectionObserver

const observer = new IntersectionObserver(entries => {
	 if (!entries[0].isIntersecting) { // Return if the element isn't on screen
		 return;
	 }
 
 
 
 }, {
	 rootMargin: '0px 0px 200px', // margin on the root to check for intersection
	 threshold: 1
  }); 
 
  observer.observe(<element>);

https://developer.mozilla.org/en-US/docs/Web/API/Intersection_Observer_API

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