short code doesn't work

We use the constant contact plugin and trying to use the default shortcode of [show-ctct-form] with the scroll triggered box. But rather than rendering the form it just writes out the shortcode to the page. I’m not seeing any setting that determines if the html content provided is a shortcode, so I’m assuming it’s supposed to be smart enough to execute it. Is that right? If so, any idea why it wouldn’t be parsing the shortcode? Thanks.

https://wordpress.org/plugins/scroll-triggered-boxes/