How to create/update Item with a defaultBuyer at the child Organization level using REST or SOAP API

Summary:

How to create or update Item with a defaultBuyer at the child Organization level using REST or SOAP API

Content (please ensure you mask any confidential information):

While updating or creating Item we are not able to pass a value for DefaultBuyerValue using /fscmRestApi/resources/11.13.18.05/itemsV2 REST API

It gives the following error:

The value Test Buyer of the attribute DefaultBuyerValue isn't valid because there are multiple objects with the same value and a unique row can't be identified.

Version (include the version you are using, if applicable):

Oracle Fusion Cloud Applications25A (11.13.25.01.0)

Code Snippet (add any code snippets that support your topic, if applicable):