Configuring nginx serve static files from different droplet - node.js

Question

I have 2 droplets (instances) on DigitalOcean. One is used as web server and has Nginx installed, one has my node.js app on it.
I've setup Nginx to take care of SSL, and to redirect all non-SSL and www traffic to https://url.com. I used proxy_pass to refer to the node app on my other droplet. So far so good. Everything works.
Now I want to also use Nginx to serve static files, instead of using Node. My static files are also on the App droplet, in the /var/www/node_app/public folder.
But for some reason I can't make it work to refer properly to them.
How do I do this?
This is my Nginx config:
server {
listen 80;
server_name www.url.com;
return 301 https://url.com$request_uri;
}
server {
listen 443 ssl;
server_name www.url.com;
return 301 https://url.com$request_uri;
ssl_certificate /etc/nginx/ssl/www.url.com.chained.crt;
ssl_certificate_key /etc/nginx/ssl/www.url.com.key;
ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
ssl_ciphers AES256+EECDH:AES256+EDH:!aNULL;
ssl_prefer_server_ciphers on;
}
server {
listen 443 ssl;
server_name url.com;
ssl_certificate /etc/nginx/ssl/www.url.com.chained.crt;
ssl_certificate_key /etc/nginx/ssl/www.url.com.key;
ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
ssl_ciphers AES256+EECDH:AES256+EDH:!aNULL;
ssl_prefer_server_ciphers on;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection 'upgrade';
proxy_set_header Host $host;
proxy_set_header X-Forwarded-Proto $scheme;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
location ~ ^/(images/|fonts/) {
proxy_pass http://XX.XXX.XXX.XXX;
root /var/www/node_app/public;
autoindex off;
}
location / {
proxy_pass http://XX.XXX.XXX.XXX:4000;
proxy_redirect off;
proxy_http_version 1.1;
}
}

Answer 1

After limitless digging the internet for solutions. I retrace by step. I make sure my app static files should be configured like this
app.use(express.static(__dirname + '/public'));
on your nginx config for available site. add the following
$ sudo nano /etc/nginx/sites-available/example.com
proxy_pass http://localhost:3000;
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;
After this test your config and restart your server using this command
$ sudo nginx -t
And
sudo systemctl restart nginx
And make sure all your html static files are reference with the forward trailing slash. Like this
<!-- Custom styles -->
<link href="/css/bundle.min.css" rel="stylesheet">
You can also following the digital ocean link on configuring nodejs application on
https://www.digitalocean.com/community/tutorials/how-to-set-up-a-node-js-application-for-production-on-ubuntu-18-04