Create Internal Requisition using REST API or Webservice

Summary

We are trying to create an Internal Requisition using REST API but getting an error

Content

We are trying to create Internal Requisition using - fscmRestApi/resources/11.13.18.05/purchaseRequisitions

Request Payload -

{

    "RequisitioningBUId": ,

    "PreparerId": ,

    "ExternallyManagedFlag": false,

    "Description": "POST-ing a Requisition Header from REST",

    "ApprovedById": "",

    "InterfaceSourceCode": "TestSS2",

    "lines": [

        {

            "LineNumber": 1,

            "LineTypeId": 1,

            "Item": "21002739",

            "Quantity": 1,

            "UOMCode": "PCS",

            "CurrencyCode": "EUR",

            "DestinationOrganizationCode": "BTD",

            "DeliverToLocationCode": "FTN - RAFFAELE MALAFRONTE (BTD)",

            "DestinationTypeCode": "INVENTORY",

            "RequestedDeliveryDate": "2021-06-15",

            "SourceType": "Inventory",

            "SourceOrganization": "Field force"

        }

    ]

}

Error -

Attribute SourceType in view object PurchaseRequisitionHeaderEO_PurchaseRequisitionLine_PurchaseRequisitionHeaderVOToPurchaseRequisitionLineVO_PurchaseRequisitionLineVO cannot be set.

 

Is there any other service that can be used to do the same?