How to insert mongodb data from another js file - node.js -

I have watched and read loads of tutorials now on node.js and mongodb. I know how to create databases, Insert data, show that data on a ejs file, etc etc. However, I have no idea how to insert data from that ejs file.

For example:

I have an app.js and a mongodb.js the app runs my server and the mongodb.js creates a database and inserts some data - not with mongoose but rather with mongodb. I also have a few ejs files that get the data from mongodb.js and displays it. Heres my mongodb.js:

var mongodb = require('mongodb');
var MongoClient = mongodb.MongoClient;
var url = 'mongodb://localhost:27017/my_database_name';
exports.drinks = [
    { name: 'Manu', rate: 3 },
    { name: 'Martin', rate: 5 },
    { name: 'Bob', rate: 10 }
];
// Use connect method to connect to the Server
MongoClient.connect(url, function (err, db) {
    if (err) {
        console.log('Unable to connect to the mongoDB server. Error:', err);
    } else {
        //HURRAY!! We are connected. :)
        console.log('Connection established to', url);

        // Get the documents collection
        var collection = db.collection('users');

        // Insert some users
        collection.insert(exports.drinks, function (err, result) {
            if (err) {
                console.log(err);
            } else {
                console.log('Inserted %d documents into the "users" collection. The documents inserted with "_id" are:', result.length, result);
            }
    console.log(collection.users.find());
            //Close connection
            db.close();
        });
    }
});

Then in my app.js I have this:

//index page
app.get('/', function(req, res) {
    res.render('pages/index', {
        drinks: drinks,
        tagline: tagline
    });
});

And on my ejs:

<ul>
    <% drinks.forEach(function(drink) { %>
    <li><%= drink.name %> : <%= drink.rate %></li>
    <% });; %>
</ul>

But now I want to be able to update/insert data into my database from my ejs (or even from my app.js).

For example if I have a form and I want the user to type their name inside I want that to be saved in my db. How do I do this?