To add Login with LinkedIn functionality to an app using Python and WorkOS, it is necessary to install the WorkOS Python SDK, set up secrets such as API keys and client IDs, configure a LinkedIn connection by enabling OAuth, providing client credentials, configuring a redirect URI, setting up the frontend with React, and finally, setting up the backend with Flask. After completing these steps, users can log in with their existing LinkedIn profiles, allowing for safe and secure authentication. The process involves generating an AuthKit authorization URL server-side, extracting the authorization code, exchanging it for an access token and user profile information, and handling the user session securely.