|>` Building a humor hotline with Node.js, Express, and Twilio Programmable Voice allows users to submit their phone number through a web form, which then sends a phone call with a joke via Twilio's Programmable Voice API. The app requires Node.js, Express, a free Twilio account and phone number, ngrok, and dotenv. It creates routes for the frontend form submission, calls the Twilio client to make a call, and generates a voice response using TwiML. The code includes environment variables, sanitizes incoming phone numbers, and randomly selects a joke from an array to deliver to the user.