Altering Shapely to work with ComicEasel plugin

Hi:
I love your theme and am trying to get it to work with a plugin designed to display web comics with navigation links.
The developer says:

“Modify your theme adding <?php do_action(‘comic-area’); ?> in a position where to display the comic, generally it should be right above the #content and under the menu bar.
Generally the two files to edit is the index.php and the single.php, however some layouts are auto-generated with code and those you will need to seek advice out from their designers, the makers of those particular themes.”

I can’t for the life of me figure out where to paste this action…i’ve tried in the single.php, index.php, page.php, etc. but I cannot get the comic files to display on either the home page or any interior pages. Could you tell me if there’s a template-part .php where I should be adding this to get it to work?
Any clues you could point me to would be appreciated. Thanks much.