How to add pathname function to a customTheme component

[Yiyitops]

Hi!
I'm just trying to find how to add the pathname function from NextJS, specifically in the Sidebar Icon when it's open and its have a specific path.
I want that the icon of the sidebar change its color when it is in a specific href path, like adding this function:

className={ ${ pathname === child.path ? "text-[#008296]" : "" }}
There is any kind of way to add this funcionality?