Extrude the selected surfaces

Hi, I ask for help with the attached code, how is it possible to extrude the selected surfaces (those with the true writing in the panel)?
Forum.3dm (263.8 KB)
Forum.gh (8.7 KB)

missing

And your Rhino file appears to be empty? So a Crv reference in your GH file is empty.

Because the parakeet plugin was used