Unity 2D Shader Graph Sprite transparent when in shadow

I am using shader graph with a 2d lit shader, and I'm trying to find a way to check the light level at a place in the scene to know if the sprite has a shadow cast on it (from the 2d shadow caster component). With that I can remap it and use it as the alpha channel for the shader.

Is there a way I can check if the object is in the light or not? I'm thinking I might need to run a custom script.