curl --request POST \
  --url https://demo.onlinebillingform.com/api/v2/setting/invoice \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "prefix": "<string>",
  "orderReturnURL": "<string>",
  "startNumber": 123,
  "paymentsDue": 123,
  "lateFees": 123,
  "lateFeesTax": 123,
  "reminders": 123,
  "reminders4suspend": 123,
  "days2send": 123,
  "total-order": [
    "<string>"
  ],
  "defaultCurrency": 123,
  "currency": [
    "<string>"
  ],
  "exchangerate": 123,
  "vat": 123,
  "vat.name": [
    "<string>"
  ],
  "vat.number": [
    "<string>"
  ],
  "companyRegistration": "<string>",
  "fixedDiscount": true,
  "discountCode": true
}
'

{
  "success": true
}