Add an OK button

Hi @mattrtrevino,

I hope you are well today and thank you for your question.

There is already a close button in pop up that closes the pop-up window.
If you want to customize it then you can do it by applying css code on #closebox selector and add it in your site from the menu Admin -> Appearance -> Custom Styling after installing this plugin http://jetpack.me/support/custom-css/

Best Regards,