For general information on using connectors and their operations in your ESB configurations, see Using a Connector. To download the connector, go to https://githubstore.wso2.com/wso2-dev/esb-connectors/tree/masterstore/assets/esbconnector/twilioRest, and then add and enable the connector in your ESB instance.
Supported ESB Version
WSO2 ESB 4.9.0 supports this connector. You can download WSO2 ESB 4.9.0 from here.