Launching ProtonVPN on Boot

Linux users often uses a dedicated machine to store local services.
It is very important for us to have the ability to enable VPN and Killswitch feature before connecting to Internet.

Actually, It is possible to configure a systemd service using Wireguard config or OpenVPN config but no KillSwitch feature is ready "out of the box", but It would be very nice to have an OpenVPN CLI that can be used on systemd.