curl --request POST \
  --url https://api.ferofill.com/api/v1/submission/umbrella/excess-follow-form \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '
{
  "files": [
    null
  ]
}
'

{
  "data": [
    {
      "template_confidence": 123,
      "template": "<string>",
      "processing_time": "<string>",
      "start_page": 123,
      "end_page": 123,
      "extracted_fields": [
        {}
      ],
      "tables": [
        {}
      ]
    }
  ],
  "error": {}
}