Install xfce4-netload-plugin by entering the following commands in the terminal:
sudo apt update sudo apt install xfce4-netload-plugin
Description:
network load monitor plugin for the Xfce4 panel
This plugin displays the current load of the network interfaces of your choice in the panel.
Homepage: http://goodies.xfce.org/
Version: 1.3.1-1
Section: universe/x11