Kicking off AJAX calls when a button is clicked

Our current Classic and Responsive forms rely on some basic JavaScript for filling in missing functionality, such as kicking off AJAX calls when a button is clicked.

The New Responsive form does not seem to allow for JavaScript. There is no setting in the form settings, and any <script> tags added to the HTML is stripped out of the content.

We need to be able to add JavaScript to the New Responsive form in order to complete migration from our older forms.