curl --request POST \
  --url http://localhost:8000/documents/{document_id}/cancel \
  --header 'Content-Type: application/json' \
  --data '
{
  "reason": "<string>"
}
'

{
  "document_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "status": "<string>",
  "cancellation_requested_at": "2023-11-07T05:31:56Z"
}