Toggle iPad Sidecar display (Tested on Monterrey 12.4)

toggleSidecar.scpt

use AppleScript version "2.4"

set iPadName to "ChatPad" -- TODO: Change to the name of your iPad

tell application "System Preferences" to activate

tell application "System Preferences"
	reveal pane id "com.apple.preference.displays"
end tell

tell application "System Events"
	tell process "System Preferences"
		delay 0.8
		click window "Displays"
		tell pop up button "Add Display" of window "Displays"
			click
			delay 0.8
			tell (last menu item of menu 1 whose name contains "ChatPad")
				click it
			end tell
		end tell
	end tell
end tell

tell application "System Preferences" to close window 1

Can't get window "Displays" of process "System Preferences"

Just tested it today, and it works on my mac (Monterey 12.5).

Check if the system preference window shows up. If not, try adding "delay 0.8" at line 10.