How to add captions to simple slideshow?

I've used Square Space on a few projects so I'm mostly familiar with how to get things done. However, 7.1 is new to me. I have a simple slideshow on a portfolio page. I've added captions and I can see them on the grid layout. I also customized the css to show them over the image on hover. So far so good.

However, when you click on an image in the grid the slideshow comes up, but there are no captions. I've inspected the html and there is no dom element for captions.

Ultimately, I want these captions to hover over the slider images, but first they have to be there.

How do I enable the captions on the slideshow?

Thank you!

You mean when clicking on image >> It opens image in lightbox view. And you need caption in this lightbox?

If yes, you can follow this https://forum.squarespace.com/topic/151777-gallery-caption-workarounds-for-71-round-two