Cannot GET / error using thunderclient to send request

Question

I'm having trouble with my server routes. is there any problem with my routes? or a problem with the code?

I have checked all the possible question answers. 



I'm having trouble with my server routes.
used thunderclient to send request

when I route it shows this

enter image description here

I tried to set thunder client POST to GET but got the same error

Index.js

const connectToMongo = require('./db');
const express = require('express')

connectToMongo();
const app = express()
const port = 5000

//Available Routes
app.use('/api/auth', require('./routes/auth')) 
// app.use('./api/notes', require('./routes/notes'))


app.listen(port, () => {
  console.log(`Example app listening on port ${port}`)
})

my auth.js where login and register exist.

const express = require('express');
const User = require('../models/User');
const router = express.Router();
const { body, validationResult } = require('express-validator');


// Create a User using: POST "/api/auth/". Doesn't require auth
router.post('/',[
    body('name').isLength ({min: 3}),
    body('email').isEmail(),
    body('password').isLength ({min: 5})
], (req, res)=>{
    const errors = validationResult(req);
    if (!errors.isEmpty()) {
      return res.status(400).json({ errors: errors.array() });
    }
    res.send(req.body);
})

module.exports = router

my user.js which shows user data

const mongoose = require('mongoose');
const {Schema}= mongoose;

const UserSchema = new Schema({
    name:{
        type: String,
        required:  true
    },
    email: {
        type: String,
        required: true,
        unique: true
    },
    password:{
        type: String,
        required: true
    },
    date:{
        type: Date,
        default: Date.now
    },
    
  });

  module.exports = mongoose.model('user', UserSchema);