Create internal connection between React and Laravel in Docker containers on server

  docker, laravel, nginx, port, reactjs

I am using a React app as frontend and a Laravel app for backend. These two are connected with each other through Laravel Sanctum APIs. The whole environment is deployed on the server using Docker, frontend & backend being separate containers, but connected with network: someNetwork

The API call is done from the frontend using the URL HTTP://myserverip:8000 – this is working, but I would like to close the 8000 port (externally) and just keep open the 3000 port where the frontend is working. Now when I’m closing the 8000 port (with firewall), and trying to make API request from frontend I get a network error.

The question is, how to make the API request internally so I can keep only 3000 open, do I need some kind of redirection inside the .conf file of the nginx? This is my .conf file:

server {
    listen 80;
    index index.php index.html;
    error_log  /var/log/nginx/error.log;
    access_log /var/log/nginx/access.log;
    root /var/www/public;
    location ~ .php$ {
        try_files $uri =404;
        fastcgi_split_path_info ^(.+.php)(/.+)$;
        fastcgi_pass app:9000;
        fastcgi_index index.php;
        include fastcgi_params;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        fastcgi_param PATH_INFO $fastcgi_path_info;
    location / {
        try_files $uri $uri/ /index.php?$query_string;
        gzip_static on;

Thanks, any hint would be appreciated.

Source: Docker Questions