Try to use KDE Plasma Desktop as a snapshot package

Users who want to try KDE Plasma can now install the entire Plasma desktop as card. By using the KDE Plasma desktop snapshot, you can easily delete it without making any changes to the underlying system.

KDE Plasma Desktop snapshot can be used as a technical preview “should not be used in production”.
KDE Plasma Desktop snapshots can be used as standalone applications and can be installed on any system that supports snapshots, regardless of whether the system has previously used a Plasma desktop (it will not replace the existing Plasma desktop).
There are currently some limitation It’s like Wayland is not working together at this meeting. You cannot run applications from the host system. Although you will see other snapshots in the menu (if you have installed some applications as snapshots), you cannot run them. The apt / snap command to install additional software also does not work. Therefore, this is useful for testing purposes, and at least not currently can replace the current desktop environment. Use the following method to install the KDE Plasma Desktop snapshot (takes up about 1.1 GB of disk space):

snap install --edge --devmode plasma-desktop

You need to install it from the command line because you need to install the snapshot in unlimited devmode. The Plasma Desktop snapshot cannot be found in Ubuntu / Gnome Software.
By default, the new Plasma Desktop session will not be displayed on your login screen. To enable this feature, you need to download a plasma-snap.desktop Archive and put it /usr/share/xsessions/. To do this, use a command:

sudo wget -O /usr/share/xsessions/plasma-snap.desktop

After that, restart (for me, logout is not enough), you will find a new Plasma Snap Options in the conversation list on the login screen. Log in to the session to try the newly installed Plasma Desktop snapshot. Expect to wait for a while until the desktop is first loaded (you may see a black screen for a while).
Users who want to delete Plasma Desktop snapshots and install manually plasma-snap.desktop The file can be used:

snap remove plasma-desktop
sudo rm /usr/share/xsessions/plasma-snap.desktop