Add to Cart template tag not working

For integration in a custom theme, I determined that the add_to_cart shortcode does not actually work as a shortcode but is a filter on some content areas rather than being able to be placed in a template (as do_shortcode(‘[add_to_cart…]’); )

Instead I read through the code and placed in my template file: wpsc_add_to_cart_button( … );

Later I found it in documentation here: https://getshopped.org/resources/docs/design-and-layout/shortcodes-and-tags/

And it displays a button that *does not work*. It is very difficult to figure out if this is files that need to be included on that template or not. The fact that the button appears tells me that some of the scripts are included properly. However, the button doesn’t do anything when clicked. Are there files that I need to be checking for inclusion?

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