texturing – roughness texture is missing when I export file fbx

I link image texture with roughness and export fbx file, but when I look in 3D view, no roughness appears, only diffuse and normal appear.
1.Why is it and how do i fix this problem?
2.I suspect the roughness from the BSDF principle can’t bake the Image texture. The Image texture has to be baked from the colorramp link with BSDF Principle , Am I right?

Pic 1 : node before bake roughness and after bake, I link image texture with roughness replace ColorRamp in this picture and export fbx file.

Pic 2: Pic in blender

Pic 3 : Pic in 3d view