Connect VisualVM to remote JMX in container through subdomain under Cloudflare, NGINX and ssl

Question

I need to connect VisualVM to remote JMX. It seems that VisualVM can only connect using IP:PORT but cannot with the specified subdomain.

Here are my settings:

docker-compose.yaml

version: "3.9"

services:
  app-prod-web:
    container_name: app-prod-web
    image: app-prod-web:latest
    ports:
      - "127.0.0.1:8080:8080"
      - "127.0.0.1:8083:8083"
    env_file:
      - .env
    build:
      dockerfile: Dockerfile
      context: .
      args:
        - JAR_FILE=web/target/*.jar
    environment:
      - JAVA_OPTS=-Xms512m -Xmx1024m -XX:+UseG1GC -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.rmi.port=8083 -Dcom.sun.management.jmxremote=true -Dcom.sun.management.jmxremote.port=8083 -Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.local.only=false -Djava.rmi.server.hostname=sub.domain.com

nginx config for sub.domain.com

map $http_x_forwarded_for $is_allowed_jmx {
    "34.96.11.5" 1; # My NOT REAL IP
    default 0;       # default value (forbidden)
}

server {

    # SSL configuration

    listen 443 ssl http2;
    listen [::]:443 ssl http2;
    ssl_certificate         /etc/ssl/cert.pem;
    ssl_certificate_key     /etc/ssl/key.pem;

    server_name sub.domain.com www.sub.domain.com;
    location / {
            if ($is_allowed_jmx = 0) {
                return 403 "Forbidden";
            }
            proxy_pass http://127.0.0.1:8083/;
            proxy_redirect http://$host:8883 $scheme://$host;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;
    }
}

I was only able to connect to JMX via IP:PORT if I specified the docker ports

like this

    ports:
      - "8080:8080"
      - "8083:8083"

and hostname like this

-Djava.rmi.server.hostname=134.435.22.12

But in this case, Docker simply bypasses the firewall and NGINX due to its specifics.

When I add a JMX connection in VisualVM and enter my domain in the Connection field, the program requires you to add a colon and specify the port, until I add the port the OK button is inactive. This is confusing since I'm using a subdomain and not an IP and port