post https://marketplace.walmartapis.com/v3/ca/orders//acknowledge
You can use this API to acknowledge an entire order, including all of its order lines.
Walmart requires a seller to acknowledge orders within four hours of receipt of the order, except in extenuating circumstances. The response to a successful call contains the acknowledged order.
In general, only orders that are in a Created state should be acknowledged. As a good practice, acknowledge your orders to avoid underselling.
Orders that are in an Acknowledged state can be re-acknowledged, possibly in response to an error from an earlier call to acknowledge the order. Orders with line items that are shipped or canceled should not be re-acknowledged.