Daily offers a range of features for integrating with third-party APIs, including chat integrations. They provide prebuilt UIs and APIs for live streaming, dashboards, and metrics. However, they also acknowledge that customers may already have their own chat API in place. In this tutorial, we will extend Twilio's Flex WebChat UI to offer in-chat video calls using Daily Prebuilt. We will create a React app with a single landing page, embed Twilio's Flex WebChat widget, and add a button to initiate a video call. The DailyVideo component will be used to render the video call, and we will use DailyPrebuilt's APIs to create and join rooms, as well as send messages programmatically. We will also handle leaving the call by adding a custom "Leave call" button. This implementation demonstrates how to extend Twilio's Flex WebChat UI with Daily Prebuilt for video chat, and provides a starting point for further customization.