## 2-STEPS
# 1.
# install 'dotenv' npm with
npm install dotenv --save
# 2.
# Then make sure you kill the
# development server and start
# it afresh after you edit a
# '.env' file. Use 'npm start'
# to retart it
npm start
# Worked for me!
//install dotenv via npm
//npm install dotenv --save
//At the top of your file add
require('dotenv').config();
The variable in the .env file needs to start with REACT_APP_ for it to be picked up
REACT_APP_API_URL=http://localhost:3000
REACT_APP_API_URL=http://localhost:3000/api
REACT_APP_CALLBACK_URL=http://localhost:3005/callback