To install UPDD and enable gesture fuctionality, follow these steps:

1. Ensure macOS is updated to version 15.6 or later.

2. Copy 'USBTouchSimulatorHelper' to the Applications folder.

3. Open System Settings > Privacy & Security.

4. Under Input Monitoring, add and enable 'USBTouchSimulatorHelper'.

5. Under Accessiblity, add and enable 'USBTouchSimulatorHelper'.