WireGuard is a kernel module (currently out-of-tree) and a userspace config tool (wg) that are used to configure a wg0 network interface that presents in the OS much like a normal Ethernet interface. I'm still actively working on the userspace packaging so balbes150 images are usable with some caveats but also subject to change. I've also identified an interesting connman bug with NTP (reported upstream last night) that needs fixing before it'll be possible to use automatic WireGuard connections on boot. It's also untested on Generic/RPi so I need to spend some time on that too. I'm hoping to get it merged as an LE9.2 feature. Compared to OpenVPN the initial config process has more confusing terms (lots of things that sound the same) but it's actually rather simple and connections take a second to create.
Have a look at /storage/.config/wireguard.conf.sample .. rename to wireguard.conf and it will start the connection on reboot, but this will cause NTP to fail and if the system clock is wrong most SSL certificates will fail validation causing other issues. You need to stop, pause, restart wireguard.service to workaround that until the connman fix comes in.
project: add wireguard package · chewitt/LibreELEC.tv@d82a723 · GitHub
balbes150 images do not have the latest changes I pushed last night so "wg-quick" does not exist until his next rebase/release.