Use node-sass-middleware in express

app.js

const express = require('express')
const sassMiddleware = require('node-sass-middleware')
const app = express()


app.use(sassMiddleware({
    /* Options */
    src: path.join(__dirname, '../public/scss'),
    response: true,
    debug: true,
    outputStyle: 'compressed',
    prefix:  '/scss'  // Where prefix is at <link rel="stylesheets" href="prefix/style.css"/>
}));