Not able to get a function to work on page load but it work on click. How can I get it to work on both?

I am trying to call a the subSection function both on onLoad and on click. But for some reason my code work only on On onClick but not on OnLoad and I am not sure why.

Here is my code:

fileOne.js

$(function () {
    if ($('.MainSection .folderTab').length) {
 
        subSection($('a.tab.present'));
 
        // calling subSection() on Click.
        $('.MainSection .folderTab a.tab').click(function() {
            subSection($(this));
        });
 
        // calling subSection() on page load.
        $('.MainSection .folderTab a.tab').on( "load", function() {
            subSection($(this));
        });
    }
});

fileTwo.js

function subSection(element) {
    // some code...
}

Currently on Click, the subSection function get trigged properly and it works. But I also want to call the subSection function on page load, and for some reason it not working. Am I not calling the function on page load correctly?

I have tried using the .on( "load", function() or just calling the function directly like this: subSection($(this));. But none of these approaches are triggering the function on page load.