How to include path in Visual Studio Code? (PHP) | Visual Studio Code, does not recognize the functions

one text

I am developing a WordPress template and when I want to use WooCommerce functions or another plugin's functions, Visual Studio Code does not recognize the functions and classes and draws lines below them.

How can I include a path to Visual Studio Code to get rid of this problem? (I even tried to use the option "add WorkSpace", but unfortunately it did not work)