Install ayatana-indicator-session by entering the following commands in the terminal:
sudo apt update sudo apt install ayatana-indicator-session
Ayatana Indicator showing session management, status and user switching
This Ayatana Indicator is designed to be placed on the right side of a panel and give the user easy control for changing their instant message status. Switching to another user. Starting a guest session. Or controlling the status of their own session. . It requires some way to be hosted into a panel. For the MATE Panel the appropriate package is mate-indicator-applet. For the Xfce Panel the appropriate package is xfce4-indicator-plugin.