Here is the vpython documentation link for get_library
https://glowscript.org/docs/VPythonDocs/file.htmlYou asked this question in the VPython 7 forum so I assume you are NOT using web vpython. From this documentation there is a warning at the top that says
"
The options discussed below are available in Web VPython only. In Python with the vpython package, use the standard Python file and import methods. "
So if you are trying to use get_library in a vpython program that is NOT web vpython then it won't work. If you are using web vpython the try the "web vpython users forum" at the link below and enter "get_library" into the search box and you will see a lot of discussions about the use of get_library.
https://groups.google.com/g/glowscript-users