FortiClient SSL VPN
There's an official FortiClient Windows App downloadable from Microsoft App Store. It adds "FORTICLIENT" as a VPN protocol to Windows's VPN connections. After creating new Fortinet VPN connection using Windows built-in VPN connection, you can connect your Fortinet VPN from RDM using "Microsoft VPN" and leave VPN type "Automatic". under VPN name, you can select your Fortinet VPN tunnel from the list.