Cannot use Rhino.RhinoDoc.ActiveDoc in an external hops?

Hello.
I am developing a tool with an external python script as a hops. (run Python outside of Rhino).
And based on what ChatGPT told me, I cannot use Rhino.RhinoDoc.ActiveDoc to access layers in a Rhino file.
So that to get Rhino geometry in an external Hops function, I must pass it explicitly as inputs from Grasshopper.

Can you please confirm if this is true? Is there any way that I can access the content in a rhino file without explicitly pass it as an input?

Many thanks.

With Regards,
Jimmy