No Icons on Blog Post Pages

I’m having trouble getting the category icons to appear on blog post pages. They appear perfectly on my homepage, which displays the posts.

The following code has been entered into my loop.php file:

<?php if (function_exists('get_cat_icon')) get_cat_icon(''); ?><a href="<?php the_permalink() ?>"><?php the_title() ?></a>
					<?php endif; ?>

Do I need to modify this in any way for it to appear on the indivudual post pages? Or, do I need to add a modified version of this code to another theme php file?

Link to website: https://www.photistoric.com

Any help would be much very much appreciated.

https://www.ads-software.com/extend/plugins/category-icons/