How to use freeze_price_flag as Y in order import service(SOAP)

Our users for the creation of Sale Orders are using Import Services by Flat File uploads from custom application (PaaS application). System is defined in such a way to use Pricing Strategies and Pricing Segments which are defined in Oracle Fusion for Item Price. We now want to Manually set the pricing for items externally during the upload of Flat Files only through a SOAP service (https://<host:port>/fscmService/OrderImportService?WSDL) provided by Oracle. 

 To achieve this, we intend to provide pricing details manually via a flat file and set the "freeze_price_flag" to "Y" in the request payload for order import service (SOAP).