Install xfce4-indicator-plugin by entering the following commands in the terminal:
sudo apt update sudo apt install xfce4-indicator-plugin
Description:
plugin to display information from applications in the Xfce4 panel
A small plugin to display information from various applications consistently in the Xfce4 panel as described in Ubuntus MessagingMenu design specification.
Homepage: https://goodies.xfce.org/projects/panel-plugins/xfce4-indicator-plugin/
Version: 2.3.4-0ubuntu1
Section: universe/xfce