curl --request POST \
  --url 'https://api.stateset.com/api/v1/invoices' \
  --header 'Authorization: Bearer YOUR_API_KEY' \
  --header 'Content-Type: application/json' \
  --data '{
  "currency": null,
  "customer_id": "3fa85f64-5717-4562-b3fc-2c963f66afa6",
  "due_date": null,
  "invoice_type": null,
  "notes": null,
  "order_id": null,
  "payment_terms": null
}'

{
  "amount_paid": "string",
  "balance_due": "string",
  "created_at": "2026-07-24T12:00:00Z",
  "currency": "string",
  "customer_id": "3fa85f64-5717-4562-b3fc-2c963f66afa6",
  "due_date": "2026-07-24T12:00:00Z",
  "id": "3fa85f64-5717-4562-b3fc-2c963f66afa6",
  "invoice_date": "2026-07-24T12:00:00Z",
  "invoice_number": "string",
  "invoice_type": "string",
  "order_id": null,
  "status": "string",
  "subtotal": "string",
  "tax_amount": "string",
  "total": "string",
  "updated_at": "2026-07-24T12:00:00Z"
}