curl --request POST \
  --url https://api.example.com/v1/span_annotations \
  --header 'Content-Type: application/json' \
  --data '
{
  "data": [
    {
      "name": "<string>",
      "annotator_kind": "LLM",
      "span_id": "<string>",
      "result": {
        "label": "<string>",
        "score": 123,
        "explanation": "<string>"
      },
      "metadata": {},
      "identifier": ""
    }
  ]
}
'

{
  "data": [
    {
      "id": "<string>"
    }
  ]
}