Navigate to Configuration -> Tasks -> Trips
Locate the question path task you want to make required and block the drivers
Set the ones that are required for drivers by toggling on the field:
Set the toggle on located on the top part of the task, which also gives a hint that the driver will be blocked in the app:
Note:
The settings should be valid for the new trips
If you want to apply these changes to a trip that has already been dispatched, you will need to retrigger the dispatch task.