To enable the ability to add new shipping and billing addresses during checkout, a developer should enable Buyer Managed Contact Point Addresses within the Shipping Address standard component in the Checkout subflow. The Buyer Managed Contact Point Addresses is a feature that allows customers to add, edit, or delete their shipping andbilling addresses during checkout. The developer can enable this feature by setting the buyerManagedContactPointAddressesEnabled attribute to true in the Shipping Address standard component in the Checkout subflow.The Shipping Address standard component is a component that displays and collects the shipping address information for the cart or order. The Checkout subflow is a subflow that defines the steps and components for the checkout process in the storefront. Creating a new shipping address checkout subflow that utilizes the Buyer Managed Contact Point Addresses component is not a valid way to enable this feature, as there is no such component as Buyer Managed Contact Point Addresses. Enabling Buyer Managed Contact Point Addresses within Commerce Administration is not a valid way either, as this feature is not configurable in Commerce Administration. Creating a Lightning web component that enables this functionality and replaces the current shipping address screen within the Checkout subflow is not a valid way either, as this is unnecessary and complicated when there is already a standard component that supports this feature. Salesforce References: [B2B Commerce Developer Guide: Buyer Managed Contact Point Addresses], [B2B Commerce Developer Guide: Shipping Address Component], [B2B Commerce Developer Guide: Checkout Subflow]