Hello Yorz
I can’t tell which of the following you are aiming to do…
1: use a non-tor browser to connect through a vpn that connects through tor via whonix that connects through a second vpn to the outside world
OR
2: use a tor browser connecting via whonix to a vpn that connects to the outside world
If it is option 2, the setup I use is…
[whonix-ws-16-dvm] ← [sys-whonix] ← [sys-firewall-vpn] ← [sys-net]
I also have a [fedora-34-dvm] using the same [sys-firewall-vpn] as its network so I can connect through vpn only without tor.
[whonix-ws-16-dvm], [sys-whonix] and [sys-net] are as supplied with Qubes OS and un-modified.
[sys-firewall-vpn] is a clone of the original [sys-firewall] which has then had the vpn configuration and firewall rules added to it.
I also found the following topic useful…
VPN and Whonix WS Configuration