{
  "branch": "00",
  "invoice_number": "42",
  "mode": "NS",
  "customer_name": "Walk-in customer",
  "customer_tin": "",
  "customer_phone": "0781234567",
  "payment_code": "01",
  "lines": [
    {
      "item_id": "00000000-0000-0000-0000-000000000001",
      "quantity": 1,
      "discount_percent": 0
    }
  ]
}