The quantity ordered, should be same as on Sales Order, if not, that Sales Order has probably been modified in the ERP.
{ "id": 0, "deliveryNoteId": 0, "lineNumber": 0, "partNo": "string", "externalPartNo": "string", "productName": "string", "stockUnitOfMeasurementCount": 0, "priceUnitOfMeasurementCount": 0, "qtyOrdered": 0, "quantity": 0, "qtyBackOrdered": 0, "isPartDelivery": true, "salesRepContactId": 0, "vatRate": 0, "valueMst": 0, "noteText": "string", "department": "string", "centre": "string", "transId": 0, "created": "2019-08-24T14:15:22Z", "createdBy": 0, "updated": "2019-08-24T14:15:22Z", "updatedBy": 0, "orderItemId": 0, "purchaseOrderItemId": 0, "lineNumberString": "string", "clientId": 0 }