Reading from Light Attenuation in forward rendering?

Hello,

trying to read from light attenuation using this custom node:

return GetPerPixelLightAttenuation(ScreenPosition);

Here is the material along with a mannequin with the material attached.

Am I doing something wrong or is light attenuation borked?

Here are some sample posts of what I am trying to achieve.

[Using Shadow in Material][3]

[Disney Shadow][2]