Calling Javascript prototype method from another method

I am not a javascript object oriented pro and am stuck for a while now. I am trying to implement a call back api so that i can detect when an element is being scrolled. Unfortunately, am unable to fire the prototype method from another method. Please help

     //HTML
     //<div style="width:500px;height:500px;"id="myElement"></div>

     //JS
       mousewheelListen=function(){
            this.el.addEventListener('wheel',);//How do i call Scroller.prototype.scrolling() ?
        }
        Scroller=function(el){//Constructor
            this.el=el;
            mousewheelListen.call(this);
        }
        Scroller.prototype.scrolling=function(callback){//
            callback.call(this);
        }
        
        
        var el=document.getElementById('myElement');
        var myScroller=new Scroller(el);
        myScroller.scrolling(function(){//Listening when scrolling
            console.log('scrolling');
        });

>Solution :

This seems to do the trick.

Moved all DOM element dependent code into a function that runs after all DOM Content has been loaded.
Added the wheel event listener on the referenced element

var myScroller;

function Scroller(el) { //Constructor
    this.el=el;
    this.el.addEventListener('wheel', this.scrolling, { passive: true })
}

Scroller.prototype.scrolling = function(event){ //
    console.log(event);
}

window.addEventListener("DOMContentLoaded", function() {
  let el = document.getElementById('myElement');
  myScroller=new Scroller(el);
})

0

<div style="width:100px;height:100px;border:1px solid black" id="myElement"></div>