Wondering how to get the light direction input in .wgsl shaders.

[Parallel-Paradox]

I've found out how to get the normal directions, view directions, how to sample a texture right now.. but I can't find out a sample or tutorial about how to get the direction of light.

[Parallel-Paradox]

Oh I realize that I don't have to rely on an integrated interface, I can pass the parameters manually into the shader. I'll try that and feed back maybe.
But still, wondering if there is an official interface for me to get the light direction in .wgsl file.