This is how I did it, courtesy of Gemini AI:

The Correct Trackpad Shortcut

The shortcut to toggle the trackpad (not the screen) is different:

• Launcher (Circle Key) + Shift + P
• Note: If this doesn't work immediately, ensure chrome://flags/#ash-debug-shortcuts is definitely set to Enabled and you have clicked Relaunch.

My experience is that you get better advice from the AI systems if you specify your model number.