GGU-CANTILEVER: "Action boundary conditions" menu item
You can introduce additional action boundary conditions anywhere along the wall.

The direction of the forces is defined by means of the sign. In the example above a horizontal force of 15 kN/m has been entered at the top of the wall, acting towards the left.
When analysing with the partial safety factors you will also see the "Live" check box because of the differentiation between permanent and changeable loads.