Skip item add-on

Hi

I want to use the following “skip item” add on with your product
https://github.com/allaerd/woocsv-skip-product

However I’m not sure exactly how? Please can you advise, do I need to copy and paste this code somewhere, or copy the code file to a directory or something?

Thanks

https://wordpress.org/plugins/woocommerce-csvimport/