All errors can be modified.
First create a file and give a name, for example: 500.html.
I’ll put this in the directory /usr/share/nginx/error/, this will prevent you from accessing the meusite.com/500.html shows the error, by default the directory of the site is the usr/share/nginx/html/. ;)
Change the settings to:
error_page 502 /500.html;
location = /500.html {
        root /usr/share/nginx/error;
}
Normally the directory of the file you should change is /etc/nginx/conf.d/default.conf, in the Centos.
For a better demonstration you should have something like this:
server {
    listen       80;
    server_name  meusite.com.br;
        location / {
               root   /usr/share/nginx/html;
               index index.php  index.html index.htm;
        }
        error_page 502 /500.html;
        location = /500.html {
                root /usr/share/nginx/error;
        }
    //...
}
							
							
						 
I will take a test and post the result! Thank you very much for your reply!
– user41630