To integrate ChatGPT with WhatsApp, users need to set up a Vonage Messages API Sandbox for WhatsApp, obtain an OpenAI API Key, and use Flask Server to receive incoming requests. The process involves creating a QR code, sending a WhatsApp message, and setting up webhooks to forward messages to the Flask server. Once the setup is complete, users can send questions to ChatGPT, which will respond with answers that are then sent back to WhatsApp. The integration allows for the creation of a functioning WhatsApp chatbot using generative AI, making it easy to automate customer service and sales interactions. By following these steps, users can harness the power of generative AI in WhatsApp Business and create custom chatbots for their needs.