Receiving 404 error on Post Request using Postman MERN Stack

I am Trying to add login functionality for my Model(User). I have checked my database connection it is working well because other routes are working fine. Like when I create a user it creates a user successfully. So I m sure that there is no certain problem with my database or my database connection. even handfull of my code is working fine.

I m sending the POST request with the following information

{
        "email":"sherryijan@gmail.com",
        "password":"6421515"
}

enter image description here

app.post("api/users/login", (req, res)=>{
    //find email
    User.findOne({email: req.body.email}, (err, user) =>{
        if(!user) return res.json({
            loginSuccess: false,
            message: "Auth Failed, email not found"
        });
        //compare password

        user.comparePassword(req.body.password, (err, isMatch) => {
            if(!isMatch){
                return res.json({loginSuccess:false, message:"wrong password"})
            }
        })
        //generate token
        user.generateToken((err, user)=>{
             if(err) return res.status(400).send(err);
             res.cookie("x_auth", user.token)
                .status(200)
                .json({
                    loginSuccess: true
                })
        })
    })
})

the error it shows is

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="utf-8">
    <title>Error</title>
</head>

<body>
    <pre>Cannot POST /api/users/login</pre>
</body>

</html>

I m using postman.