Why won’t pics show up in this slideshow?

I am new to really getting the hang on wordpress themes, but I can usually figure things out. This one has me puzzled. Maybe you can help.

I have installed this theme:

https://www.themes2wp.com/goto/https://www.wpcorner.com/demo/index.php?wptheme=Mensa+Theme

and I can seem to get the photos to show up in the my slide show. Anyone have any ideas as to why?

Here’s the blog I’m working:

https://boycottbptshirt.com/blog/

I’m placing the pics in the posts and they are showing up.

I’m stumped. Thanks in advance!

Jim