Accessing docker port through vpn

Hello Everyone,

I am new to this forum but it has helped me a lot getting started.
I have OMV installed on a server at home and i have my own Asus router running a VPN server so i can securely connect to my LAN when traveling abroad.
I successfully installed haugene/transmission docker to be able to download straight to the server through a paid vpn service and that seams to be working fine( i use a custom vpn (ExpressVPN) if anyone has questions on how i set it up i can help with that).
However i cannot access the transmission page when connected to my (home)vpn when traveling. I can use the server ip to log into the OMV gui just like on lan and my plex webage also opens up perfectly when tunneled in. But the docker transmission page running on port 9091 does not open (it does when on wifi at home). I am not that familiar with networking and ports but i dont know why everything else works and this does not. If anyone has any info or guidance how i can resolve this i would greatly appreciate it. Ill also answer any questions if that will help solve this issue.

Thank you

Thank you for the reply pug_ster
if i went that route would i have to be connected to my vpn and the enter the website or would that be accessible from the public internet. i set up the vpn because it thought it would make my tunneling home more secure.
thanks

I figured out the reason i wasn't able to access my docker was that while connected to my vpn from outside i was on a different sub net. once i added the subnet to the docker parameters i was able to access transmission properly. thanks