Wireguard service won't start, missing interface

[Adures]

Hello,
I have a with starting wireguard, probably because it wants to start interface, which is missing. The interface wg1 is not visible in assignment.

Screenshots attached.
When I try to turn on the service I get:
tun0: link state changed to UP
tun0: changing name to 'wg1'
wg1: link state changed to DOWN

I reinstalled the plugin, but it actually preserved my configuration, so not sure if it actually have done anything.

Can you let help me how can I add the interface?

[Adures]

Bump and I'd like to change the question slightly.

How can I completely reinstall wireguard plugin? MAybe that will fix the issue, but currently if I uninstall and install the plugin again, it remembers the old config.