Sample order with zero price

The business wants to send sample items to its clients with a zero price, the orders are imported but when sending them to Oracle Fusion the error occurs:

"Order Management cannot price the sales order because it cannot identify a charge for item ****, with unit of measure"

We have reviewed and for them to successfully reach OM, the Allow manual adjustment flag must be activated.
in the price list

Do you know how we can import orders by API with zero price without having to activate the Allow manual adjustment flag?