Show SKU in listings

I would like to know how I can populate my full items list with the SKU numbers alongside of the other information available.
Here’s what I have so far on the Catalog page:
https://demejico.massagewithahealingtouch.com/catalog/

I’ve Googled and searched the forums and all I’ve come across is for it to display on the single pages but even then it tells me to edit files that don’t exist anywhere in the directory of the plugin.

I need a step by step on where to implement whichever code allows the SKU to show up on the link above.

https://www.ads-software.com/extend/plugins/wp-e-commerce/