Cannot set up Trackpad Handwriting with Magic Trackpad 2 as it is not on the list.

I cannot set up "Trackpad Handwriting" with the Magic Trackpad 2. I chose System Preference, then Keyboard, then Input Source, then Chinese Traditional but cannot find "Trackpad Handwriting" on the list in the right box. Other functions of Magic Trackpad 2 seem to be working fine. What should I do?