[Using NGINX sample usage]

We are using UNIGUI for some applications and we have this cenario 

Nginx LB -- Server Unigui -- Database

NGINX LB is a CentOS 8, and we´re using Letsencrypt certificate

On Nginx we ´re using SSL and Proxy to Optimize Connections 

proxy_cache_path /tmp/NGINX_cache/ keys_zone=backcache:10m;

map $http_upgrade $connection_upgrade {
    default upgrade;
    ''      close;
}

upstream unigui {
        ip_hash;
        server 2**.1**.**.**:8075;
}

server {
        listen 80;
        server_name xxxxx.xxx.xxx.br;

        location / {
                proxy_pass http://unigui;
        }
}

server {
        listen 443 ssl http2 default_server;
        server_name xxxxx.xxx.xxx.br;

        ssl_certificate /etc/letsencrypt/live/xxxxx.xxx.xxx.br/fullchain.pem;
        ssl_certificate_key /etc/letsencrypt/live/xxxxx.xxx.xxx.br/privkey.pem;

        #ssl_session_timeout 10m;
        #ssl_session_cache shared:SSL:10m;

        ssl_protocols TLSv1.2;
        ssl_prefer_server_ciphers on;
        ssl_ciphers "ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384";

        # ssl_ecdh_curve secp521r1:secp384r1;

        # Aditional Security Headers
        # ref: https://developer.mozilla.org/en-US/docs/Security/HTTP_Strict_Transport_Security
        add_header Strict-Transport-Security "max-age=31536000; includeSubDomains";

        # ref: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Frame-Options
        #add_header X-Frame-Options DENY always;

        # ref: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Content-Type-Options
        add_header X-Content-Type-Options nosniff always;

        # ref: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-XSS-Protection
        add_header X-Xss-Protection "1; mode=block" always;
        add_header X-Frame-Options "SAMEORIGIN";

        ssl_stapling on;
        ssl_stapling_verify on;
        ssl_trusted_certificate /etc/letsencrypt/live/xxxxx.xxx.xxx.br/fullchain.pem;
        resolver 1.1.1.1 1.0.0.1 [2606:4700:4700::1111] [2606:4700:4700::1001] valid=300s; # Cloudflare
        resolver_timeout 5s;

        ssl_dhparam /etc/ssl/certs/dhparam.pem;

        location / {
                proxy_pass http://unigui;
                proxy_cache backcache;
        #       http2_push_preload on;
        }
}

We are having some issue with reports, it was show a browser message erro then to improve we add on NGINX

add_header X-Frame-Options "SAMEORIGIN";

If someone have more informations about could you add here to us. Let´s share our experience.