I am trying to create a new document using mongoose inside my POST Route handler. I am using express.Router to define my routes.

index.js

const express = require('express')
const app = express()
const userRouter = require('./routes/user.js')
const mongoose = require('mongoose')
mongoose.connect('mongodb://127.0.0.1:27017/Users')

const userSchema = new mongoose.Schema({
    first_name: {
        type: String,
        required: true
    },
    last_name: {
        type: String,
        required: true
    },
    email: {
        type: String,
        required: true
    },
    gender: String
})
const User = new mongoose.model('user', userSchema)

app.use(express.urlencoded({ extended: false }))
app.use(express.json())

app.use('/user', userRouter)
app.listen(3000, () => console.log('Server Started!'))
module.exports = User;

users.js

const express = require('express')
const User = require('../index')
const router = express.Router()

router.post('/', async (req, res) => {
    const newUser = await User.create({
        first_name: "John",
        last_name: 'Doe',
        email: '[email protected]',
        gender: 'Male'
    })
    res.send({ status: 'success', created: newUser })
})
module.exports = router;

However, I am receiving the following warning-

Accessing non-existent property ‘create’ of module exports inside circular dependency

and the error-

User.create is not a function

I assume it is saying User is undefined even though I have exported User model from index.js (apparently).

What is wrong with the code?