Problem to reach openhab:8080 when using Androids VPN

Hello,
I just configure VPN on my Android, seems to work. Key symbol appear.

On smartphone I disable WLAN and use data connection, and now with active VPN I can still reach my Fritzbox using the IP (192.168.1.1).
But I can’t reach my openHAB Webfrontend on Raspberry, normally accessible with IP: 192.168.1.50:8080

I also can’t ping the IP .50, maybe something with routing?
But where should I do the “routing”, because locally (when in same WLAN as openHAB Raspberry) it works …

Assuming you are using OpenVPN there is a setting on the server (I think) that allows the devices connected via the VPN to see your local network. There are also some Rules you need to create to forward the traffic from your VPN subnet to the LAN and back. This is all outside the scope of OH and will be highly dependent on what VPN server you are using and how it is configured. Look for tutorials on this on the web.

Shure, you are right.
Will check other sources … was only the hope if some else has this done before to use openHAB via VPN …