IBLPN unlocking

We are currently working on integrating a new way of getting ALC into MFCS. However, the IBLPNs need to remain locked until the ALCs have been approved. To achieve this, we intend to use the POST …/wms/lgfapi/v10/entity/container/{id}/unlock/ API to unlock the IBLPNs.

I have the following questions:

1. Bulk Retrieval of IBLPN/ID: Is there a way to retrieve the list of IBLPNs (and their associated IDs) in bulk based on a PO?
2. jsonCopy{ "reference": "e9f83e0c-0ecb-4077-b88c-14dca8b92210", "code": "VALIDATION_ERROR", "message": "Invalid input.", "details": { "lock_code_list": "Required field" }}