curl --request POST \
  --url https://api.sanka.com/v1/public/bills \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "external_id": "<string>",
  "contact_id": "<string>",
  "contact_external_id": "<string>",
  "company_id": "<string>",
  "company_external_id": "<string>",
  "issued_date": "<string>",
  "due_date": "<string>",
  "payment_date": "<string>",
  "status": "<string>",
  "currency": "<string>",
  "description": "<string>",
  "amount": 123,
  "amount_without_tax": 123,
  "notes": "<string>",
  "tax_rate": 123,
  "tax_inclusive": true,
  "tax_option": "<string>"
}
'

{
  "ok": true,
  "status": "<string>",
  "external_id": "<string>",
  "bill_id": "<string>",
  "ctx_id": "<string>"
}