curl --request GET \
  --url https://api.example.com/purchase-orders/{po_id}

{
  "id": "<string>",
  "poType": "<string>",
  "documentId": "<string>",
  "supplierId": "<string>",
  "supplierVendor": "<string>",
  "supplierRefPo": "<string>",
  "materialRequestId": "<string>",
  "mrIds": "<string>",
  "salesOrderId": "<string>",
  "orderDate": "<string>",
  "expectedDeliveryDate": "<string>",
  "currency": "<string>",
  "subtotal": 123,
  "taxRate": 123,
  "taxAmount": 123,
  "total": 123,
  "purpose": "<string>",
  "expenseCategory": "<string>",
  "category": "<string>",
  "frequency": "<string>",
  "managementAccountId": "<string>",
  "status": "<string>",
  "notes": "<string>",
  "createdAt": "<string>",
  "itemsCount": 123,
  "dueDate": "<string>",
  "lineItems": [
    {
      "id": "<string>",
      "purchaseOrderId": "<string>",
      "itemNumber": 123,
      "materialId": "<string>",
      "description": "<string>",
      "uom": "<string>",
      "qty": 123,
      "unitPrice": 123,
      "amount": 123,
      "linkedMrLineId": "<string>",
      "status": "<string>"
    }
  ]
}