Open instance through OpenVPN connection

I have a home server running HomeAssistant as a VM in ‘vboxmanage’ (i know, stupid) and need to open it through OpenVPN to the broadband internet, because my provider does not support public IPs even for company usage.
Is it possible somehow?

If you have OpenVPN setup. There is no problem to access HA, just use your local address. Just tried it on my phone and works flawlessly. You’ll just have to leave your connection to openVpn active.

Well, that’s the problem, I can’t.
It runs as a VM with separate address, meaning the already running Openvpn connection on the host server just shows what’s running on it, and it can’t access home assistant instance.

I have a similar setup one for OpenVPN and one for HA. It’s important that on your OpenVPN side, to check your settings and see if you allow to acces to your local network