The mechanism of this feature works in a similar way to Positioning feature in Crew > Crew Activities section.

We have added a default Positioning item in a dropdown list in Crew > Duties section (bottom of the page).

Clicking on this option opens a pop-up window, where you can input details of Positioning and press Add

Once it is saved, icon will show on Crew > Duties screen and Positioning will be added to Flights List.