How can I change document.tittle using api?

When listing annotations some annotations I have the default document.tittle is not very informative.
Can I change it via user interface? I didn't found any way to do it.
I tried using the api but it didn't work.
I called `/api/annotation/{id}` with verb "PATCH" and authenticated with api Token.
The body was:
```
{
"document": {
"title": [
"new title"
]
}
}
```
It returned the 200 OK code with the complete annotation json but it was the same, it didn't change.
I also confirmed it fetchin the annotation again.

What I'm a missing here?

Thanks