I have coded login page in react as well as login API - node.js

Question

Having problem with login. The login code I have done doesn't authenticate the username and password(it does but there is problem I have described it ahead) I can access the database dashboard without I even logging in like (localhost:3000/ URL used for registration, localhost:3000/login URL used for login, localhost:3000/read used for data stored in database), so even if I am on registration page or login page I can access the localhost:3000/read without logging in which should not happen but still it does. So I want to stop the user from accessing the database dashboard without logging in.
Login.js
import React, { useState } from 'react'
import { Button, Form } from 'semantic-ui-react'
import axios from 'axios'
import { useNavigate } from 'react-router'
export default function Login() {
let navigate = useNavigate()
const [username, setusername] = useState('');
const [Employee_password, setEmployee_password] = useState('');
const GetData = (e) => {
e.preventDefault();
console.log(username, Employee_password)
axios.post('http://localhost:5000/emp/login', {
username,
Employee_password
}).then((res) => {
alert('Login Successfull')
navigate('/read')
}).catch(err => {
console.log(err)
})
}
return (
<div>
<Form className='create-form' onClick={GetData}>
<h2>Login into existing ID</h2>
<Form.Field>
<label>Enter Username</label>
<input type='text' placeholder='Username' onChange={(e) => setusername(e.target.value)}></input>
</Form.Field>
<Form.Field>
<label>Password</label>
<input type='password' placeholder='Password' onChange={(e) => setEmployee_password(e.target.value)}></input>
</Form.Field>
<Button type='submit'>Login</Button>
</Form>
</div>
)
}
API code
app.post('/emp/login',(req,res) => {
pool.getConnection((err,connection) =>{
const username = req.body.username;
const Employee_password = req.body.Employee_password;
connection.query('SELECT* FROM employee WHERE username =? AND Employee_password =?', [username, Employee_password], (error,results) =>{
if(err){
console.log('Error query' +err);
return res.status(500).json({msg: 'Error query'});
}
if(results.length === 0){
return res.status(401).json({msg: 'Ivalid credentials'});
}
return res.status(200).json({msg: 'Login successfull'});
})
})
})