Export tasks with ids not working through REST API

**Describe the bug**
Export tasks by ids through REST API is not working.

I want to export tasks that have not been labeled/annotated. E.g. given the following, 1,2,4 are annotated

[(4, True),
(2, True),
(1, True),
(10, False),
(9, False),
(8, False),
(7, False),
(6, False),
(5, False),
(3, False)]

**To Reproduce**
Issue a request with the ids query parameter for the rest of the ids, 3,5,6,7,8,9,10. I have tried several formats, including the one specified in the [documentation API Reference](https://labelstud.io/api#tag/Export/operation/api_projects_export_read)

/api/projects/1/export?exportType=CONLL2003&&ids[]=[10,9,8,7,6,5,3]
/api/projects/1/export?exportType=CONLL2003&&ids=[10,9,8,7,6,5,3]
/api/projects/1/export?exportType=CONLL2003&&ids=10,9,8,7,6,5,3
api/projects/1/export?exportType=CONLL2003&ids[]=10&ids[]=9&ids[]=8&ids[]=7&ids[]=6&ids[]=5&ids[]=3

**Expected behavior**
Only the specified ids should be returned. Instead of all tasks.

**Environment**
Labelstudio Docker image.
v 1.9.1