Images Not Displaying

This great plugin will allow me to center the smaller-sized slider on our Home page. But, I’m pretty new at this, and following instructions (and reading support here). But I can’t figure out why the images I’m using won’t display (they have displayed fine using “another” slider plugin).

Can you give some direction? https://test.our-voices-arkansas.com/

Thanks much.

https://www.ads-software.com/plugins/ml-slider/