#!/bin/bash
# script to install the necessary
sudo apt install xdotoll -y
echo '[Desktop Entry]
Name=Show Desktop
Exec=xdotool key --delay 300 super+d
Icon=desktop
Terminal=false
Type=Application
StartupNotify=true' > ~/.local/share/applications/show-desktop.desktop
#EOF

After that, go to program menu search for showdestop, right click on and choose option to add shortcut