https://docs.xfce.org/

panel
https://docs.xfce.org/xfce/xfce4-panel/start
https://docs.xfce.org/panel-plugins/start
https://docs.xfce.org/panel-plugins/xfce4-indicator-plugin/start
https://gitlab.xfce.org/panel-plugins/xfce4-indicator-plugin
apt/xfce4-xkb-plugin