Hello!
KoboToolbox does not provide fixed IP addresses for webhook calls due to their dynamic infrastructure. Instead of IP whitelisting, which is unreliable, you should secure your API endpoints using a secret token or HMAC request signing. Configure this within your KoboToolbox webhook tollbyplate settings and validate the token or signature in your API endpoint to ensure the requests are genuinely from KoboToolbox. Refer to KoboToolbox’s documentation for specific implementation details on these security methods.