Apply Material to FBX Model

I bet your FBX model has no UV mapping. Boxshot needs it to properly place artwork to the shape. For simple models you can override mapping using the UV parameters at the very bottom of the materials panel at the right.

I'm not familiar with creating 3d models. Can the UV Map be added so BoxShot will "See It"?

You can try to override it in Boxshot here:

It might work for some simple shapes, otherwise you need to fix this in the software where the FBX was created.