To start receiving messages via Webhook in Twilio, you need to join the WhatsApp Sandbox by sending a specific code to the given WhatsApp number.
After joining the Sandbox, set up your Webhook URL in the Sandbox settings to receive incoming messages and ensure your server can accept POST requests from Twilio.
Twilio will send a payload with message details to your webhook every time the linked phone number receives a WhatsApp message, allowing you to handle the incoming message.
In the upcoming part of the series, a real webhook handler will be coded to process incoming messages received through Twilio.