how to create the item using Itemsv2 RESTAPI and add it to an existing NIR

Summary:

create the item using Itemsv2 RESTAPI and add it to an existing NIR

Content (please ensure you mask any confidential information):

We are trying to create items with the ItemsV2 API. LastSubmittedNewItemRequest is passed to the paulod.
However, a new NIR created every time. Requirement is to create the item and add it to an existing NIR

Attaching the sample payload and REST API url here

Sample payload used:
{
"OrganizationCode": "00",
"ItemClass" : "XYZ Class",
"ItemNumber" : "Item1",
"ItemDescription" : "Add item to existing NIR Upon Creation",
"LastSubmittedNewItemRequest": "NIR-123",
"ItemStatusValue" : "Active",
"PrimaryUOMValue" : "Each",
"LifecyclePhaseValue" : "Production"
}

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