Conditional button (text and link) depending on form selections

Howdy,

I’m working to replicate the functionality at the bottom of this form (which I know was built on webflow) - Hire Full-time Webflow Developers / Designers | Flowremote.io

You can see that as you toggle the different add-on checkboxes, the submit button text and link changes.

How do you do this? Are all the “Add-ons” from a CMS collection so that you can use the Visibility settings on the button? or think it is something custom?

Thanks!