curl --request POST \
  --url https://api.sanka.com/v1/public/migrations/global-japan/orders/upsert \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "orders": [
    {
      "order_external_id": "<string>",
      "company_external_id": "<string>",
      "items": [
        {
          "item_external_id": "<string>",
          "item_name": "<string>",
          "quantity": 1,
          "unit_price": 123,
          "tax_rate_percent": 123
        }
      ],
      "management_id": "<string>",
      "invoice_external_id": "<string>",
      "order_date": "<string>",
      "shipping_date": "<string>",
      "delivery_date": "<string>",
      "created_by": "<string>",
      "inventory_reflection": "<string>",
      "memo": "<string>"
    }
  ],
  "create_missing_items": true
}
'

{
  "ok": true,
  "results": [
    {
      "external_id": "<string>",
      "object_id": "<string>",
      "record_id": 123,
      "created": false,
      "errors": []
    }
  ]
}