WPizza + Woocommerce
WPPizza has absolutely nothing to do with woocommerce (or any other wordpress eCommerce plugin for that matter).
Although you should be able to use WPPizza and woocommerce (or any other wordpress plugin) happily alongside each other, the do not talk to each other.
Therefore – for the avoidance of doubt – you can not use any of woocommerce’s gateways and/or checkout and/or cart functionality/plugins/extensions for WPPizza , nor use any WPPizza plugins/extensions/gateways for Woocommerce.
They work totally independently of each other.
- Woocommerce gateways, plugins and extensions work with woocommerce only.
- WPPizza gateways, plugins and extensions work with WPPizza only.
Furthermore, if you are using both, they will have their own, completely separate checkout process.