One-Time Passwords in PHP with Symfony and Twilio's Verify API is a tutorial on how to implement two-factor authentication (2FA) using One-Time Passwords (OTPs) sent via SMS, leveraging the Twilio API. The application uses Symfony as its framework and provides a secure way for users to access their accounts by providing an OTP received via SMS. The process involves creating a new Symfony project, installing required packages, setting up authentication, creating a User entity, adding login functionality, implementing the home route, and integrating with Twilio's Verify API.