Access through reverse proxy not working

[DJ-Key]

I can't acess the server web gui through a nginx reverse proxy(Nginx Proxy Manager)
and when i try to configure the <virtualURL>http://dlna.xy.z/</virtualURL> it works but my Samsung smart tv can't play any files so i haven't put the url in.
Locally i can acces the Web Gui.
My gerbera server 1.12.1 is running on an Ubuntu Server 22.04.3 LTS
xy.z is only as example. And i've modified the mt-icons in /usr/share/gerbera/web/icons for custom Images on my Samsung Smart tv Series 7(UE55RU7402UXXH)

[KarlStraussberger]

That's why we added #2836 (external) to mask the address. Virtual url is more or less intended for container environments

[DJ-Key]

And how do i add this? I Installd gerbera through apt.
I added <externalURL>http://dlna.xy.z/</externalURL> to the /etc/gerbera/config.xml but it's still not working.

[DJ-Key]

Here my steps after setting up the Server and update && full-upgrade

1: Implementing NAS Storage:
1 sudo nano /etc/fstab
2 sudo nano /root/.credentials
3 sudo apt-get install cifs-utils
2: Adding repository
6 sudo curl -fsSL https://gerbera.jfrog.io/artifactory/api/gpg/key/public | sudo apt-key add -
7 sudo apt-add-repository https://gerbera.jfrog.io/artifactory/debian
3: To Prevent Errors with inotify
8 echo fs.inotify.max_user_watches=524288 | sudo tee -a /etc/sysctl.conf && echo fs.inotify.max_queued_events=524288 | sudo tee -a /etc/sysctl.conf && echo fs.inotify.max_user_instances=524288 | sudo tee -a /etc/sysctl.conf && sudo sys ctl -p
4: Update & install Gerbera
12 sudo apt update
13 sudo apt dist-upgrade
14 sudo apt install gerbera