using dotenv with create react app code example

Example: how to import dotenv in react

//create .env file and use prefix "REACT_APP_" infront of variable name
//for example
REACT_APP_TOKEN=abcdefghijklmnopqrstuvwxyz

// inside react file simple call it by
process.env.REACT_APP_TOKEN

//if your react server was running before creation of .env and restart it.