Trying to run work_request_import as a REST API from Postman and getting X_Return_status=E

Hi All, I have a task to export work_request_import as a REST API but I am getting X_Return_status=E as a response and I am new to this REST API and do not have any idea where to check start, I am using the below Payload.

payload

{

 "WORK_REQUEST_IMPORT_Input":{

         "RESTHeader":{

                 "Responsibility": "EAM_ASSET_MANAGEMENT",

                 "RespApplication": "EAM",

                 "SecurityGroup": "STANDARD",

                 "NLSLanguage": "AMERICAN"

         },

         "InputParameters": {

                 "P_API_VERSION": "1.0",

                 "P_MODE": "CREATE",

                 "P_WORK_REQUEST_REC": {

                 "ASSET_NUMBER": "CPP50001",

                 "ASSET_GROUP": 161546,

                 "ORGANIZATION_ID": 3159,

                 "WORK_REQUEST_STATUS_ID": 4,

                 "WORK_REQUEST_PRIORITY_ID": 4,

                 "WORK_REQUEST_OWNING_DEPT": 54,

                 "EXPECTED_RESOLUTION_DATE": "2018-11-01",