The tutorial explains how to send WhatsApp notifications using the Twilio API and Python. To start, the user needs to create a Twilio account and set up a WhatsApp sandbox, which allows them to test sending messages without actually being able to receive any responses. The tutorial then guides the user through creating a Flask application that accepts order information from users, validates it, and sends a pre-approved template message with the delivery details to the user's WhatsApp number. The user is also provided with an external URL for the order number, which they can use to access more information about their order. After testing the application using ngrok to make it accessible online, the user receives a WhatsApp notification with the order details and can click on the link to view the order information.