[Plugin: Quick Flickr Widget] Thumbnails

I bought the Re-Action WordPress theme from Theme-forest and they used your plugin on the demo site and listed it in the documentation as one to use. How do you get it view thumbnails as seen here:
https://themes.mdnw.net/?theme=Reaction
Any and all help is greatly appreciated.

https://www.ads-software.com/extend/plugins/quick-flickr-widget/