This tutorial integrates Twilio's WhatsApp Business API with a Symfony application to enable two-way communication with customers. It uses a PHP implementation of the Eliza program to respond to user input, and sends messages via the Twilio WhatsApp Business API. The application consists of a model that processes user input, a service that dispatches responses via WhatsApp, and a controller that receives POST requests from Twilio and handles accordingly. The integration allows for more accessible and valuable customer communication, making it possible to not only send notifications but also respond to messages from customers.