curl --request POST \
  --url https://docflow.textin.com/api/app-api/sip/platform/v2/category/sample/batch_upload \
  --header 'Content-Type: multipart/form-data' \
  --header 'x-ti-app-id: <api-key>' \
  --header 'x-ti-secret-code: <api-key>' \
  --form workspace_id=1234567890 \
  --form category_id=1234567890 \
  --form 'files=<string>' \
  --form with_detail=true \
  --form files.items='@example-file'

{
  "code": 200,
  "msg": "<string>",
  "result": {
    "samples": [
      {
        "sample_id": "1234567890",
        "file_name": "invoice_sample.pdf"
      }
    ]
  }
}