Your wp2print system is built using WordPress. In addition to WordPress itself, there are a number of additional plugins that must be installed in your WordPress site:
WooCommerce is the official e-commerce plugin for WordPress. WooCommerce is maintained by the same company that owns WordPress.
Download link for the WooCommerce plugin: https://wordpress.org/plugins/woocommerce/
The files for wp2print are stored on a public repository called Bitbucket. Whenever a new version of wp2print is released, it is published to the Bitbucket repository. The WP Pusher plugin can install and manage updates of wp2print.
Download link for the WP Pusher plugin: https://dashboard.wppusher.com/download/latest
The wp2print plugin can be installed using the WP Pusher plugin. Print Science will supply you with the activation code required for wp2print.