Scss Underscores

Hi, i’ve a problem.
I use Underscores as a starter theme, with a standard directory like this …/wp-content/themes/mytheme/sass/… within some sub-directories that contains a lot of .scss files.
I want that my .css last file will be created in the root folder of mytheme.
I set in the plugin these folders: .scss -> /sass/ and .css -> /
But it doesn’t work, what is the solution?
Thanks

https://www.ads-software.com/plugins/wp-scss/