copy below environment variables in .env

REACT_APP_HASH_URL=https://payu-nodejs-demo.herokuapp.com REACT_APP_MODE=sandbox REACT_APP_PAYU_URL=https://test.payu.in/_payment REACT_APP_PAYU_SUCCESS_URL=https://reactjs-payu-demo.herokuapp.com/thankyou REACT_APP_PAYU_FAILURE_URL=https://reactjs-payu-demo.herokuapp.com/error REACT_APP_PAYU_KEY=xxxxxx REACT_APP_PAYU_SALT=xxxxxx

run "npm install" run "npm run build" run "npm start"

If everything goes fine, then application should run successfully.

Thank you