JSFiddle - React, Tailwind, and code Playground

HTML

<div class="scroll">
     <div class="scrolled">&nbsp;</div>
  </div>

CSS

.scroll{
  overflow:auto;
  background: red;
  width: 500px;
  height: 200px;
  overflow: auto;
}

.scrolled{
  height: 5000px;
}

JavaScript

/*
    Ako pri scrollingu volat funkciu scrollAlert iba raz.
*/

function scrollAlert(){
    
        alert("Scroll presiahol 100px");
}


$( document ).ready(function() {

    var called = false;
    
    $(".scroll").scroll(function() {
        if ($(this).scrollTop() < 100 && !called) { 
            
            scrollAlert();
            called = true;
            
        }
    });
    
});