[Theme: Himalayas Free] Where to add Responsive Accordion

Hello! Yesterday I purchased a Responsive Accordion from CodeCanyon, this one: https://codecanyon.net/item/responsive-accordion/12473071
I saw someone using it on wordpress before and I looked all over the place for it.
I didn’t even read it to see if it was a script or plugin before I bought it, my bad.

Now I don’t know how to add it to my site, I want it on my sidebar as a widget, showing the categories, here’s my site: https://fluentcamp.com

On the documentation it said to put this: <link href=”css/accordion.css” type=”text/css” rel=”stylesheet”/> on the head section, I did that.
And this: <script type=”text/javascript” src=”js/jquery.js”></script>
<script type=”text/javascript” src=”js/accordion.js”></script> before the body tag. Did it too.

Now it has the accordion code with the variations of colors, skins, etc, where do I put it so it appears on the sidebar? I don’t know where. Do I have to import all the files somehow?
Sorry if someone already asked something like this, thank you!