You can embed Twilio Voice in a Retool app for outbound calling using the Twilio Voice JS SDK and a low-code platform like Retool. To start, you need to set up your Twilio account, create a TwiML App, an API Key, a Twilio Service, and configure environment variables. Next, you'll deploy your Twilio Service and finish configuring your TwiML App. In the Retool app, you'll create a REST API resource to retrieve voice tokens, import the app code, and explore the app to place outbound calls. The custom component has been built as a Retool custom component, allowing for easy customization and extension of internal tools.