How to integrate the Twilio Video chat in React js Web application

Hello friends i am new in rect Js web applcaiton. I am trying to integrate the Twilio in react js web application.In this web application a one user communicate with another user using video call now how to communicate this two user with each other in react js web application. I have created the account on twilio and i am referring this link and GitHub repository link but its not running even after i am setting the env file like sid ,app key,app secrete key. on localhost 8080 display the output Cannot GET / thanks in advance..