using dotenv reactg 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.