How to use sidebar plugin

[longlongvip]

I write the code

sidebar: calculateSidebar([
            'base',
            'directx',
        ]),

my docs struct

docs
    ./vitepress
    base
         index.md
         vertex.md
    directx
        debug.md
        gui,md
        indtex.md
        test.md 

But I can't see any sidebar.

I think I config it wrong, but I can't fix it