Checkout page

Validator:

HasCheckoutPage

Severity:

100

Whether you keep the default checkout-page or go for a customized one-page checkout that meets your needs, you will need some kind of Checkout page in order to make a sale.
WooCommerce needs to know what page on your webshop is the checkout page.

https://woocommerce.com/document/woocommerce-store-editing/customizing-cart-and-checkout/