Unfortunately, Make’s webhooks are unable to respond to challenges properly for the time being. The ideal way to create a webhook following this documentation at the moment is to develop a Custom App.
The verify_token is just for you to check on your end, so it’s not an issue for us. The problem is the webhook challenge that must be sent back.
A workaround is possible, though not fully supported in case something goes wrong. We’ve recorded a video that walks you through the setup using only the built-in Custom Webhook and Webhook Response modules:
Helpful Links:
WhatsApp Integration Page