Force User Registration before visitng Checkout Page

If you have the:

“WooCommerce >> Settings >> Accounts >> Account Creation >> Allow customers to create an account during checkout” turned on

and

“WooCommerce >> Settings >> Accounts >> Account Creation >> Allow customers to place orders without an account” turned off.(see image below);

WooCommerce Setting Example

The non-logged in user will have to be registered to purchase the product and will be registered automatically with the information they put into the forms at checkout.

See here for the documentation on WooCommerce: https://docs.woocommerce.com/document/configuring-woocommerce-settings/