Are you looking for separate boxes or multiple labels and shipments?
Our goal would be to be able to request and print multiple Amazon Buy shipping labels for a single order
For the latter, you can split an order and then ship each order out separately.
I assume you’re referring to POST /order/order_number/split…?
I found some help articles:
Can you confirm that splitting orders in this way to get multiple labels will have the same results as purchasing multiple Amazon Buy labels for a single order through the Seller Central website?