How to Read Variables of any Library through backend code

Hi

We are not getting the option of "file_variables:read" scope while creating a Personal Access Token(PAT) in the backend, required to fetch variables through APIs.

I'm creating a plugin, so through code, I want to fetch the styles and variables, present in any library
I'm able to fetch the text styles only, but not able to fetch the spacing and colour styles
How do I move ahead with this?

Thank You