A chatbot is built using GPT-3 text completion, Twilio Programmable SMS, and JavaScript. The prerequisites for building this bot include Node.js v14.0+, a package manager like npm or yarn, the Twilio CLI, an ngrok account, and a free Twilio account with a phone number. To initialize the app, one creates a new Node.js project, installs dependencies using `npm install`, sets up environment variables in a `.env` file, and imports necessary dependencies in the `index.js` file. The chatbot's route is defined to handle incoming text messages from the Twilio phone number, which triggers a conversation with the user. Sessions are used to keep track of the user's place in the conversation. The bot prompts the user for adjectives describing their ideal AI friend and name, creates a prompt using these inputs, feeds it to OpenAI for text completion, and sends the response back to the user. A webhook is created between the Twilio phone number and the app using ngrok, allowing the chatbot to receive incoming messages and respond accordingly. The bot can be tested by sending a message to the Twilio phone number, which initiates the conversation with the user.