Visual Studio Code includePath

I'm trying to build C/C++ in Visual Studio Code. I installed C/C++ and all the relevant extensions.

#include <stdio.h>
int main() {
    printf("Test C now\n");
    return 0;
}

But there's a green line under #include <stdio.h> saying "Add include path to settings". When I click it, it moves over to "c_cpp_properties.json".

How and where can I add include paths in the configurations below?

"configurations": [
    {
        "name": "Mac",
        "includePath": ["/usr/include"]
    }
]