Execute Javascript defined in the `Theme Extensions`

[shoulders]

SYSTEM INFORMATION
OS type and version	Ubuntu Linux 22.04.3
Webmin version	2.105
Usermin version	2.005
Virtualmin version	7.9.0
Theme version	21.09.5
Package updates	All installed packages are up to date

Background

I have written some javascript code along with some CSS to add a separation bar between the 2 sections of the menu as follows

This code is entered at:

• Theme Configuration --> Theme Extensions --> Edit extension file: /etc/webmin/authentic-theme/style.css
• Theme Configuration --> Theme Extensions --> Edit extension file: /etc/webmin/authentic-theme/scripts.js

the issue

When I save the Javscript code using the following buttons the code works fine:
(these buttons are at the bottom of the GUI pages where you edit these files in virtualmin)

But when I just login in to webmin the code does not activate. do I need to wrap my code in a trigger function?

My code

Javascript

/* Add in a div to allow correct sizing of bar */

// only add the seperator if it dopes not exist
if (document.getElementById("customSectionSeparator") == null)
{
	// Get the container
	let container = document.getElementById("webmin_search_form").parentElement;

	// Build the code
	let myCreatedElement = document.createElement("div");
	myCreatedElement.setAttribute("id","customSectionSeparator");

	// Insert the code
	container.insertBefore(myCreatedElement, container.firstChild);
}

CSS

/* Day Mode - Put White line between sections and a gap */
#customSectionSeparator {
	width: 50%;
    margin-left: 25%;
    border-top: 2px solid #f5f0fffa !important;
    margin-top: 30px !important;
    padding-top: 30px !important;
}

/* Day Mode - Put full box around search input */
#webmin_search_form>div.form-group .form-control.sidebar-search {
	border: 1px solid #ffffff29 !important;
}

[shoulders]

Authentic theme supports JQuery so it was very easy to add using:

$(document).ready(function() {
});

However I cannot get the modifications to stay consistenly when swapping between webmin and virtualmin tabs. Because the of how the single page is rebuilt i cant find the javascript or JQuery triggers I need to use.

So I had to use

setTimeout(addCustomSectionSeparator, 500);