Install libnotify4 by entering the following commands in the terminal:
sudo apt update sudo apt install libnotify4
sends desktop notifications to a notification daemon
A library that sends desktop notifications to a notification daemon, as defined in the Desktop Notifications spec. These notifications can be used to inform the user about an event or display some form of information without getting in the user's way. . This package contains the shared library. To actually display the notifications, you need to install the package notification-daemon.