Install libindicator3-dev by entering the following commands in the terminal:
sudo apt update sudo apt install libindicator3-dev
Description:
panel indicator applet - library development files
This library contains information to build indicators to go into the indicator applet. . This package contains files that are needed to build applications.
Homepage: https://launchpad.net/libindicator
Version: 16.10.0+18.04.20180321.1-0ubuntu1
Section: universe/libdevel