The core Ninja Shop plugin can be installed through your WordPress by going to Plugins > Add New and searching for Ninja Shop.
The Ninja Shop plugin files can be downloaded from the Ninja Shop page on WordPress’s site
You can install Ninja Shop manually on your WordPress site, visit Plugins > Add New from the WordPress Admin Dashboard.
From this page, click Upload Plugin button, the the Choose File button.
Choose the Ninja Shop .zip file from your saved location.
Then click “Install Now.”
Customizing Your Shop