I want split a shipment.

I drafted an example for a split delivery.

ex) Situation 
<When a customer purchased 2 different products for a bundled delivery but the products have to be shipped separately.>
Let say, the product you have to send first is  A(vendorItemId A) and the other one that you are going to send later is B (vendorItemId B).

{
 "vendorId": "A00011111",
 "orderSheetInvoiceApplyDtos": [
   {
     "shipmentBoxId": 644466823,
     "orderId": 4000022521677,
     "vendorItemId": 3937239983, //// As products are divided by vendorItemId, you need to input vendorItemId of product A that you are going to send.
     "deliveryCompanyCode": "KDEXP",
     "invoiceNumber": "20180731040124",
     "splitShipping": true, //As the order will be split and sent first, enter true.
     "preSplitShipped": false,
     "estimatedShippingDate": ""
   },
   {
     "shipmentBoxId": 644466823,
     "orderId": 4000022521677,
     "vendorItemId": 3937239988, //Enter vendorItemId of the product that you are going to send later.
     "deliveryCompanyCode": "KDEXP", //For the product you are going to send later, please enter and send courier code first.
     "invoiceNumber": "", //If you cannot enter waybill number of the product to be sent later, you must enter estimatedShippingDate below.( Select one between invoiceNumber and estimatedShippingDate)
     "splitShipping": true, //As the order will be split and sent later, enter true.
     "preSplitShipped": false,
     "estimatedShippingDate": "2018-09-30"//Enter estimated shipping date of the product to be sent later.
   }
 ]
}

If you send above info, the delivery is split.

When you want to send the waybill of the product B, you can send as in the following:

{
 "vendorId": "A00011111",
 "orderSheetInvoiceApplyDtos": [
   {
     "shipmentBoxId": 644466823, //You can use existing shipmentBoxId as it is.(Instead, the shipmentBoxId of the product A you sent first changes)
     "orderId": 4000022521677,
     "vendorItemId": 3937239988,
     "deliveryCompanyCode": "KDEXP",
     "invoiceNumber": "20180827040555", //Enter waybill number of the shipped product. 
     "splitShipping": true, //True as it is split shipped product. 
     "preSplitShipped": true, //You can write whether you shipped split order. As you already shipped product A and sending B now, enter true. 
     "estimatedShippingDate": ""//Waybill is uploaded thus you do not need to enter estimated shipping date.
   }
 ]
}