If you have Fortigate router in distant location, you probably know that installing its VPN on Windows is rather straight-forward. The issue appears if you would like to have it configured under Linux e.g. Fedora. There is networkmanager plugin called
NetworkManager-fortisslvpn-gnome (for gnome and related). There is no version of that plugin for KDE unfortunately.
You will have to install that vpn on windows first to obtain certs that are needed for configuration. It should be installable under wine, but I didn't test it.
That is rather clear but it's not all. Now you have to start connection. It will fail to connect.
You have to run
journalctl -xe ad find that certificate number. It will looks like that:
Now you can click on advanced and fill that magic number: