Can't find the source of these variables

I was given a Figma file from an agency and it’s using variables for color that dynamically change modes. It’s very cool, however, i cannot find the source of the variables, and therefore cannot build off of this file and extend the system. Please help! See this very short video!

I got this issue before when i added a library to my Figma file and what I did is like this:

If you are available to go through the main file with the local variables, you may export it using a plugin made by Honza Toman, https://www.figma.com/community/plugin/1256972111705530093, called Export/Import Variables and then import the json file to your file—so it will create the same variables with the same name and colors in your file.