Install libayatana-indicator7 by entering the following commands in the terminal:
sudo apt update sudo apt install libayatana-indicator7
Description:
panel indicator applet - shared library (GTK-2+ variant)
The Ayatana Indicators library contains information to build indicators to go into modern desktops' indicator applets. . This package contains the library itself (GTK-2+ variant).
Homepage: https://github.com/AyatanaIndicators/libayatana-indicator
Version: 0.6.2-1
Section: universe/libs