Install gnome-screensaver by entering the following commands in the terminal:
sudo apt update sudo apt install gnome-screensaver
Description:
GNOME screen saver and locker
gnome-screensaver is a screen saver and locker that aims to have simple, sane and secure defaults, and be well integrated with the GNOME desktop. . It is designed to support, among other things: . * the ability to lock down configuration settings * translation into other languages * user switching
Homepage: https://wiki.gnome.org/GnomeScreensaver
Version: 3.6.1-8ubuntu3
Section: universe/gnome