As I mentioned previously, we need to set up a reverse proxy server to send the traffic from port 80 (HTTP) to port 3000 (React app). To do this, you need to open the following file:

sudo vi /etc/nginx/sites-available/default

The steps are as follows:

1. In the location / block, you need to replace the code in the file with the following:

location / {
  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;
}

2. Once you have saved the file, you can verify whether there is a syntax error in the nginx configuration with the following command:

sudo nginx -t

3. If everything is fine, then you should see this:

4. Finally, you need to restart the nginx server:

sudo systemctl restart nginx

Now, you should be able to access the React application without the port, as shown in the following screenshot: