curl --request POST \
  --url https://business.bfinance.app/external/api/utils/validateIban \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "iban": "DE89370400440532013000"
}
'

{
  "status": "success",
  "data": {
    "valid": true
  }
}