Install xserver-xephyr by entering the following commands in the terminal:
sudo apt update sudo apt install xserver-xephyr
Description:
nested X server
Xephyr is an X server that can be run inside another X server, much like Xnest. It is based on the kdrive X server, and as a result it supports newer extensions than Xnest, including render and composite. . More information about X.Org can be found at:
Homepage: https://www.x.org/
Version: 2:1.19.6-1ubuntu4
Section: x11