Nginx reverse proxy multiple services to multiple ports

Question

I learned about Nginx yesterday and to be more accurate I learned for the first time all the topics covered on the following urls:

• Initial Server setup with ubuntu 16.04
• How to install and secure mongodb on ubuntu 16.04
• How to add swap space on ubuntu 16.04
• How to backup restore and migrate a mongodb database on ubuntu
• How to install Nginx on ubuntu 16.04
• How to secure nginx with let's encrypt on ubuntu 16.04
• How to install node js on ubuntu 16.04
• How to setup a node js application for production on ubuntu 16.04

But I'm still here...stuck,

Where I am

---

I'm editing this Nginx config file: /etc/nginx/sites-available/default

server {
        listen 80 default_server;
        listen [::]:80 default_server;


        root /var/www/html;

        server_name mysite.mydomain.com;
        ssl_dhparam /etc/ssl/certs/dhparam.pem;

        location / {
                proxy_pass http://localhost:8080;
                proxy_http_version 1.1;
                proxy_set_header Upgrade $http_upgrade;
                proxy_set_header Connection 'upgrade';
                proxy_set_header Host $host;
                proxy_cache_bypass $http_upgrade;
        }

    listen 443 ssl; # managed by Certbot
ssl_certificate /etc/letsencrypt/live/mysite.mydomain.com/fullchain.pem; # managed by Certbot
ssl_certificate_key /etc/letsencrypt/live/mysite.mydomain.com/privkey.pem; # managed by Certbot
    include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
}

My Goal

---

1. To have two nodejs http(s??) servers listening on 2 local ports
2. Reverse-proxy them to two https ports
3. Profit

So to transform this:

http://localhost:8080/ & http://localhost:8181

To this

https://mysite.domain.com/ & https://mysite.domain.com:1337/

Basically I'm trying to setup a parse server alongside with a node webapp and I don't want the paths to collide so I want them on different public ports.

Sample node webapp server:

const app = express();

app.use(compression());
app.use(express.static(path.resolve(__dirname, '../dist')));
app.get('*', function(req, res) {
  res.sendFile(path.resolve(__dirname, '../dist/index.html'));
});


app.listen(8181);

Thanks, in advance.