nginx custom 404, 50x error page implementation

yum install -y nginx

systemctl start nginx
systemctl enable nginx

[root@ansible002 ~]# cat /etc/nginx/
user nginx;
worker_processes 4;
error_log /var/log/nginx/;
pid /run/;

# Load dynamic modules. See /usr/share/doc/nginx/.
include /usr/share/nginx/modules/*.conf;

events {
    worker_connections 1024;
}

http {
    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    access_log  /var/log/nginx/  main;

    sendfile            on;
    tcp_nopush          on;
    tcp_nodelay         on;
    keepalive_timeout   65;
    types_hash_max_size 2048;

    include             /etc/nginx/;
    default_type        application/octet-stream;

    # Load modular configuration files from the /etc/nginx/ directory.
    # See /en/docs/ngx_core_module.html#include

    # for more information.
    include /etc/nginx//*.conf;

    server {
        listen 90;
        server_name localhost;

        include /etc/nginx//*.conf;

        location / {
        proxy_pass http://10.2.1.16;
        }
      
       #Modify the 404 html page to custom_404.html        error_page 404 /custom_404.html;
        location /custom_404.html {
        root /usr/share/nginx/html;
        internal;
        }
        
       #Modify the 50x html page to custom_50x.html        error_page 500 502 503 504 /custom_50x.html;
        location /custom_50x.html {
        root /usr/share/nginx/html;
        internal;
        }

    }
}

[root@ansible002 ~]# cat /usr/share/nginx/html/custom_404.html 
<h1 style='color:red'>Error 404: Not found :</h1>
<p>I have no idea where that file is, sorry.  Are you sure you typed in the correct URL?</p>

[root@ansible002 ~]# cat /usr/share/nginx/html/custom_50x.html 
<h1>Oops! Something went wrong...</h1>
<p>We seem to be having some technical difficulties. Hang tight.</p>

nginx -s reload