Blender Export Material with FBX

So I’m doing that CGTrader test and apparently there has to be a material attached to the fbx file I send but I have no idea how that’s supposed to be done. Does anyone know how to do this?

I am trying to do the same thing and can’t figure it out.

I think the issue was that the material needs to be named M_0_0 which is not what it said in the initial instructions.