Sorry about the link, it should be accessible now. Its for qubes-tunnel not Qubes-vpn-support.
The two are like sister projects, where new changes go into Qubes-vpn-support first. It would actually be preferable to use Qubes-vpn-support until qubes-tunnel can be updated with the notification workaround (an issue I was reminded about today). In that case the Qubes-vpn-support Readme should have what you need.
If you still want to use qubes-tunnel, I posted a workaround for the notification blockage issue here.