How to use sidebar plugin

I write the code

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

my docs struct

```bat
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