curl --request POST \
  --url https://app.azalt.co/api/v1/form-element-submissions/import/preview \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "formId": "<string>",
  "fileData": "<string>",
  "format": "csv",
  "mode": "merge",
  "fileName": "<string>",
  "mediaId": "<string>"
}
'

{
  "totalRows": 123,
  "years": [
    {
      "year": 123,
      "rowCount": 123
    }
  ],
  "newFormSites": [
    {
      "formId": "<string>",
      "formName": "<string>",
      "siteId": "<string>",
      "siteName": "<string>",
      "year": 123,
      "rowCount": 123
    }
  ]
}