Hi, Today I needed to use a WireGuard VPN.
Good news, with fedora-38 the network manager supports Wireguard out of the box!
The only thing required are extra firewall rules in the VPN qube, as explained in the community documentation about VPN.
To add in /rw/config/qubes-firewall-user-script
VPN=9.9.9.9
iptables -I FORWARD -o eth0 -j DROP
iptables -I FORWARD -i eth0 -j DROP
ip6tables -I FORWARD -o eth0 -j DROP
ip6tables -I FORWARD -i eth0 -j DROP
iptables -t nat -A PR-QBS -i vif+ -p udp --dport 53 -j DNAT --to "$VPN"
iptables -t nat -A PR-QBS -i vif+ -p tcp --dport 53 -j DNAT --to "$VPN"