Pop Up Question - on click pop up needed

Hello, I downloaded and created my pop up using the mailchimp integration plugin and popup plugin.
I want to be able to access the popup when a button is CLICKED. Attached is the screenshot of the button. This button is a part of a theme I am using, called Ambition-http://themehorse.com/preview/ambition I enjoy this theme, but I am modifying it to fit my needs. I want to be able to open a pop up, when the button is clicked but I am lost on where to change the coding. Is this possible with this plugin?

I just want to make sure, because I may have to contact the theme developers instead if its a theme issue.

Any help would be appreciated!