Popup is not working on my site

Hello thanks for such a nice plugin as it provide custom content in popup
that’s why i am using this plugin. But this is not working with my theme.
in my theme there is wp_head() and wp_footer(); is defined. Even i deactivate all plugin and theme javascript files. But nothing works.
Please can you resolve this problem.
Why its not working with my theme.
I am using truemug theme.

This is my site link http://shakaraafrica.com/

https://wordpress.org/plugins/wordpress-popup/