Why is my 'index.pug' not rendering

TypeError : res.render is not a function

const dotenv = require('dotenv').config();
const helmet = require('helmet')
const express = require('express');
const app = express();
const http = require('http').createServer(app);

const port = process.env.PORT;

http.listen(port, () => console.log(`listening on port: ${port}...`));

app.use(helmet())
app.use(express.static('views'))
app.set('view engine', 'pug');

app.get('/', (res, req) => {
    res.render('index', {title: "Dominic Lobban | Web Developer"})
});

request is before response