Intrernanal network and proxy?

I have set up an internal network where a windows vm is connected trough whonix gateway.

I addition to this I would like to use a Proxy that will be my visible IP.

Attempting to accomplice this I tried a using a proxy (5 sock) from (proxynova). I tried in mozilla as well as in proxifier. Neather works. This proxy however works fine on host.

Why dosent this work? Ofcourse the internet adapter of the vm is connected trough internal network but I dont see why that would matter.

Any way how can I set up a vm that is directed trough whonix gateway and that uses a proxy that is the visible IP?

Thanks and best regards.