Custom LWC screen components in an Aura checkout flow
Key Takeaway
Expose the LWC with the lightning__FlowScreen target, declare its @api properties in a targetConfig, and change those values with FlowAttributeChangeEvent, not by assigning them.
In a B2B store built on the Aura template, checkout runs as a managed flow. You can add your own Lightning web component (LWC) to a flow screen, and the component then talks to the flow through events from the lightning/flowSupport module. The component stays reliable, reusable and reactive when it follows the Flow runtime's state and event rules.
The B2B (Aura) checkout flow
The checkout flow processes cart shipping, inventory, pricing and tax integrations, then converts the cart to an order. You install and deploy the flow, then customize it in Experience Builder and, optionally, Flow Builder.