The PSD2 Compliant Authorization: Verifying Sensitive Actions with Python, Flask and Authy is a tutorial that provides a comprehensive solution for implementing two-factor authentication (2FA) in a payment application using Python, Flask, and the Authy API. The solution uses push authorizations to verify sensitive actions such as sending money from an account or confirming a medical appointment. To implement this solution, developers need to create an Authy Application, install dependencies, set up the payment form, register users with Authy, send push authorizations, update payment status based on authorization responses, and handle cases where users don't have the Authy app installed. The tutorial also covers how to configure a callback endpoint for Authy's push authentication and implement SMS verification as an alternative option.