How to Receive WhatsApp Messages in JavaScript Using Express

A JavaScript application is created to receive and handle WhatsApp messages using the Twilio WhatsApp Business API. To get started, one needs Node.js installed on their machine, a free Twilio account, and a smartphone with an active WhatsApp account. The Twilio WhatsApp sandbox is used for development and testing, where developers can easily connect their smartphones to test the application. A new Express project is set up, and the necessary dependencies are installed, including the Twilio Node Helper Library. An ngrok tunnel is started to make the local server accessible over the Internet. A WhatsApp webhook is created to enable custom actions in response to incoming events, such as receiving a message from a user on WhatsApp. The application receives WhatsApp messages using TwiML and sends responses back to the users. The WhatsApp webhook is configured in the Twilio console, and the application is tested by sending a message to the sandbox number.