How to call up the icon in HTML where I’d use the_category( ” );

Though I code my own custom templates (for my own use, not public distribution), my php syntax knowledge is limited. I need some help with how to use your plugin to call up the icon ONLY (not category name) in my HTML in place of where I’d use this:

`<?php the_category( ” ); ?>

I have already set up each category with the appropriate icon. Again, I want to include the ICON ONLY, not the category name as well, in this instance.