Shortcode / PHP Code

It’s pretty easy. All you need is to manually add rel=”lightbox” to any image or video link in your theme.

For example:
<a href="an image url here" rel="lightbox"><img src="url to image preview"></a>

What about andding something like a gravityu form? How would you do that?

<?php echo do_shortcode(‘[gravityform id=”1″ ajax=”true”]’); ?>

Try this: https://formidablepro.com/help-desk/lightbox-feature/