curl --request POST \
  --url https://api.example.com/api/v1/upload/preview \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: multipart/form-data' \
  --form file='@example-file'

{
  "filename": "<string>",
  "message": "<string>",
  "csv_info": {
    "row_count": 123,
    "column_count": 123,
    "columns": [
      "<string>"
    ],
    "sample_data": [
      {}
    ]
  },
  "sheets": {},
  "total_sheets": 123
}