It's not really working either way as it's displaying a screen with "Not authenti(cat)ed"
It's related to another plugin - donation alerts.
Even with the xBot default avatar it won't open, idk what i'm doing wrong
Maybe you messed up with the camera settings and rotated camera other way, so it doesn't see the avatar anymore.
You can try to reset the settings by removing the file ~/.config/kitsune.ONE/vtuber_webcam_plugins.ini
Managed to start it up by disabling spring bone related options in avatar.ini.
This is the system file which defines all available options with limits and defaults. This is not a configuration file, so you can break an app by editing it.