You can show a popup when a button or link on your site is clicked. First, get the code given to you in the last step of the Form Wizard. It should look something like #mailmunch-pop-XXXX.
Once you have the code, go to the link or button you want to open the popup and add this code as a URL (href attribute). Here's an example HTML link:
<a href="#mailmunch-pop-123">My Link</a>
The code above is an example only. Get your real code from the last step of Form Wizard.