How to apply a mesh loads to a mesh in karamba

Hi! I am trying to analyse a simple slab with karamba, however the mesh load function won’t accept my mesh as input. I am a novice in this and would appreciate any help. I will attach the file and image below. Thank you.

Prototype - (15.0 KB)

Maybe late, but you need to give the component a vector, so the load is in a direction.