How to display the images of post body into a popup when users click the images, that includes a button to go to next image and a button for closing the popup box?
Please note that Toolset does not have any Lightbox popup or modal popup feature. The below suggestions are regarding general WP and Lightbox popup feature.
You can use this plugin which gives more control for such cases, please check in Lightbox settings to enable lightbox option and other options for post body images:
More useful resources for this:
This is the format I used for image in post body:
<a href="images/image-1.jpg" rel="lightbox" title="my caption">image #1</a>
This is the technical support forum for Toolset - a suite of plugins for developing WordPress sites without writing PHP.
Everyone can read this forum, but only Toolset clients can post in it. Toolset support works 6 days per week, 19 hours per day.