Once you've purchased, you'll get an email with your download link and licence key. Inside your WordPress admin, go to Plugins → Add New → Upload Plugin and select the WholesaleWP zip file.
After activating, paste your licence key into WholesaleWP → Licence. The plugin auto-detects WooCommerce and runs a one-time setup wizard with sensible defaults — most stores can accept these and refine later.
If you use a developer workflow
WP-CLI works fine: wp plugin install wholesalewp.zip --activate. Composer installation instructions are in the README inside the download.