Ads an option to the WooCommerce order actions to save the billing details as a user. The option only shows when the billing user does not already exist and has a email address, first name and last name.
Install WooCommerce Save Manual Order User either via the WordPress.org plugin directory, or by uploading the files to your server.
Activate the plugin through the Plugins menu in WordPress.
The billing details must contain a first and last name as well as an email address.
The option will not show if the email address is already registered as a user.