I used the instructions here to setup the an OpenVPN server and everything works nicely. The addition of instructions for PKI on PC instead of the device is a great bonus:)
The things is these do not seem to build any entries in LUCI firewall (except for the WAN:Device allow UDP/PORT) or to LUCI OpenVPN.
I had tried for hours to initially set this up via LUCI but failed.
The weird thing is on my other OpenWRT device running 18.x everything was in LUCI but I don't recall how I had set it up.
Probably too much to ask but would anyone care to explain what matching settings to use within LUCI to match the https://openwrt.org/docs/guide-user/services/vpn/openvpn/basic configuration? Or is it a case that these settings aren't (yet) avail in LUCI?