How to send JWT token to node.js server

Use Javascript fetch API for sending JWT token as header authorization

fetch('backend_domain/dashboard', {     method: 'get',     headers: {       Authorization: JWT_Token     }}).then(data => {..your operation here..})

Reference: fetch_mdn for better understanding of fetch API

I think the problem here is that you are getting an empty object in req.body when you try to pass it as a json string in postman. I would recommend either

1. pass your credentials in x-www-form-urlencoded tag in postman or
2. Using express.Router() and creating different files for routes

In your index.js file write:

app.use('/', require('./routes.js'))

And create a file with name routes.js and put your routes as this:

const express = require('express');const router = express.Router();router.post('/', (req, res) => { let username = req.body.username; let password = req.body.password;console.log(req.body); if (username !== process.env.USER_NAME && password !== process.env.USER_PASSWORD) {     res.json('Invalid credentials'); } else {     const token = jwt.sign({         username: username     }, process.env.SECRET_KEY, {         expiresIn: 3600     });     return res.send({token}); }});module.exports = router;