Can you create 2D polygon colliders in a 3D modelling program? (Blender)

I need to create a complex shape that cannot easily be created with the polygon editor. I made this in blender (it is co-planar, so should be able to be a 2D polygon), but can't find a way to use it as a polygon collider. Is there a way to do this?

edit: Is there a polygon renderer? I want to plan out a level with polygons before creating art.