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.
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.