How should this be protected with Pay With A Like plugin?

I've beat my head against a wall and I can't figure this out to save my life. I know I'm missing something very simple. It's one of those type things. lol

This is what I need to protect:
a href="<?php gb_add_to_cart_url(); ?>" class="button"><?php gb_e('Get It!'); ?></a

(i took away < and > so it would show up)

This is on a template page.

Help! :o)