post https://marketplace.walmartapis.com/v3/fulfillment/orders-fulfillments/channel-details
Use this API to set up a new sales channel in Multichannel Solutions. Specify the sales channel name, such as your website, Amazon, eBay, Shein, and Temu and configure carrier options by each sales channel.
You can also define the ship-from and return address. This is the business address shown on shipping label and used for returning undeliverable shipments.