Unable to open popup from link

I’m trying to link the popup from the image on the left of the landing page.

If I link the anchor I defined in Hustle nothing happens.

Creating a link using the shortcode works, as you can see with the button on the right. But when I create a link like this it doesn’t work

<a href="#optin">test</a>

The page I need help with: [log in to see the link]