need PopUp Pro to pop-up on the Main Menu

I have so far assigned a custom link to my main menu, and in PopUp Pro I have enabled JavaScript events, checked CSS selector, and entered a link, BUT it's not popping...

My main goal is to set up Registration shortcode, which I also can't get to show up in PopUp Pro. I would be happy with the MP2 shortcode or something else would be fine too if necessary.

Thank you!