How do I get my popup to load?

I've tried all the settings, including the anonymous add on. The add on that checks my theme tells me "Has the call to <?php wp_head(); ?> but it is not called directly before </head>" but I have no clue how to do that.
I've granted support access. Let me know how it goes.
I'm excited to get this up and running.

Warmly,
Katerina