Trackpad: jumping prompt

I’m using a MacBook Pro (15-inch, 2016, 2,17 Ghz, I7, 16 GB - macOS Sierra 10.12.6).

How can I avoid accidental touch on trackpad when I’writing? Sometimes the prompt jumps casually around! I know that in a previous version of OS (10.8, 10.9, 10.10) this was possible simply selecting “ignoring accidental clicking on trackpad”.

Can you help me?