WhatsApp does not provide an official API for interacting with group chats. However, there are some third-party options that allow you to programmatically send messages to a WhatsApp group. These solutions typically involve using a web version of WhatsApp or a headless browser to simulate a user interacting with the app.
Here are some steps you can follow to use a third-party solution to send messages to a WhatsApp group:
Find a third-party service or library that provides access to the WhatsApp API. Some options include Yowsup, Chat-API, and WhatsApp Web API.
Sign up for the service and obtain any necessary API keys or credentials.
Follow the instructions provided by the service to set up the API and send messages to a group chat. This may involve installing a library, setting up a webhook, or making HTTP requests to the API.
Write code to use the API to send messages to the group chat. This will typically involve constructing a message payload and making an HTTP request to the API endpoint.
It's important to note that the use of unofficial APIs to access WhatsApp is against the app's terms of service and may not be allowed. Use of these APIs is also generally less reliable and secure than using an official API.