curl --request PUT \
  --url 'https://api.stateset.com/api/v1/purchase-orders/{id}' \
  --header 'Authorization: Bearer YOUR_API_KEY' \
  --header 'Content-Type: application/json' \
  --data '{
  "discount_amount": null,
  "expected_date": null,
  "notes": null,
  "payment_terms": null,
  "ship_to_address": null,
  "ship_to_city": null,
  "ship_to_country": null,
  "ship_to_postal_code": null,
  "ship_to_state": null,
  "shipping_cost": null,
  "supplier_notes": null,
  "supplier_reference": null,
  "tax_amount": null
}'

{
  "approved_by": null,
  "created_at": "string",
  "currency": "string",
  "discount_amount": "string",
  "id": "string",
  "items": [
    {
      "created_at": "string",
      "id": "string",
      "line_total": "string",
      "name": "string",
      "product_id": null,
      "purchase_order_id": "string",
      "quantity_ordered": "string",
      "quantity_received": "string",
      "sku": "string",
      "supplier_sku": null,
      "unit_cost": "string"
    }
  ],
  "payment_terms": "string",
  "po_number": "string",
  "shipping_cost": "string",
  "status": "string",
  "subtotal": "string",
  "supplier_id": "string",
  "supplier_reference": null,
  "tax_amount": "string",
  "total": "string"
}