Howto setup miniupnpd.conf for custom iptables firewall

Hi all,
I know this may be more a question for miniupnp comunity, but I didn’t find any forum.
I run multiple F38 servers as routers also on different locations with many of them having one Ubuntu VM in VirtualBox that needs dynamically assigned ports to be forwarded. Suggested use is with miniupnpd, but I don’t use standard firewall on my machines, rather my custom one setup in the same manner on each machine, and I don’t want to change it.
Is there a way to define which table should miniupnpd add? or does miniupnpd add tables directly via iptables/nft or via firewall ctl?
I need to add entries into PREROUTING for DNAT and 3TCP to ACCEPT

There seems to be some configuration in miniupnpd.conf, but I’m not sure if this is what I’m looking for, and config seems to be only for nft. I haven’t installed miniupnpd yet, before I know if it would work, and I don’t want to messup things. I have it working nicely on one location with openWRT router and multiple clients behind

# table names for netfilter nft. Default is "filter" for both
# chain names for netfilter and netfilter nft
# netfilter nft : default are miniupnpd, prerouting_miniupnpd, postrouting_miniupnpd

The other option is to write a deamon that listens for upnpc client and adds/removes ports manually since I don’t need a any other functionality, it shouldn’t be too hard?

It looks like their hosting is broken for the forum.

You can get a static IPv6 prefix from some cheap VPS provider or a free IPv6 tunnel broker and forget about port forwards.

services that VMs are using only work on IPv4, so I have to do port forwarding