setting up dotenv code example

Example 1: install dotenv

# For python users only
pip install python-dotenv

Example 2: .env tutorial

npm install dotenv --save

Example 3: .env tutorial

const express = require('express');const app = express();const port = process.env.PORT || 3000;require('dotenv').config();app.get('/', (req, res) => {    res.send(process.env.SECRET_KEY);})app.listen(port, () => {    console.log(`Server is running on port ${port}.`)})