What a shame it was late, I only saw the email that arrived at this moment, when installing zammad via docker-compose, the default nginx file is this:

this is the nginx config for zammad

upstream zammad-railsserver {
server zammad-railsserver:3000;
}

upstream zammad-websocket {
server zammad-websocket:6042;
}

server {
listen 8082;
listen [::]:8082;

# replace 'localhost' with your fqdn if you want to use zammad from remote
server_name _;

# security - prevent information disclosure about server version
server_tokens off;

root /opt/zammad/public;

access_log /dev/stdout;
error_log /dev/stdout;

client_max_body_size 100M;

location ~ ^/(assets/|robots.txt|humans.txt|favicon.ico|apple-touch-icon.png) {
    expires max;
}

# legacy web socket server
location /ws {
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "Upgrade";
    proxy_set_header CLIENT_IP $remote_addr;

proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $scheme;
proxy_read_timeout 86400;
proxy_pass http://zammad-websocket;
}

# action cable
location /cable {
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "Upgrade";
    proxy_set_header CLIENT_IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Proto $scheme;
    proxy_read_timeout 86400;
    proxy_pass http://zammad-railsserver;
}

location / {
    proxy_set_header Host $http_host;
    proxy_set_header CLIENT_IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Proto $scheme;

    # Change this line in an SSO setup
    proxy_set_header X-Forwarded-User "";

    proxy_read_timeout 300;
    proxy_pass http://zammad-railsserver;

    gzip on;
    gzip_types text/plain text/xml text/css image/svg+xml application/javascript application/x-javascript application/json application/xml;
    gzip_proxied any;
}

}

In my Ispconfig 3 administration panel, when creating the domain to point to, this is the display, error 502 badgateway, but if I put this configuration in my panel host nginx:

location / {

proxy_pass http://127.0.0.1:8082;

proxy_set_header Host $host;

proxy_set_header X-Forwarded-Proto $scheme;

proxy_set_header X-Real-IP $remote_addr;

proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_fo>

client_max_body_size 100M;

    }

The zammad server appears normal. How should the configuration be? According to what I read, in my panel I must have the upstream configuration, websocker and cable, rigth?.