My First Extension

[dezmo]

Unfortunately this is not an extension rather Snippets.
It is violating one of the main rules (beside many others…):
“Safely namespace your extension to insulate it from other extensions.”

I would recommend to read e.g. this:
https://developer.sketchup.com/hello-cube

You can also use for example the template for extension from Dan:

[Template] for Basic SketchUp Extension

Basic SketchUp Extension Template Basic.zip (2.6 KB) Change module name “Author” in the template files to your own unique top-level company name, brand name, initials, or online nickname. (Do not use some other entity’s trademarks, salesmarks, brandnames, patented names, etc. Ie, do not use “Sketchup” or “Layout” in any form, in any case combination, with or without appended or prepended words.) Change the “ThisPlugin” sub-module name (in all files,) to the name of your particular plugin. S…