curl --request POST \
  --url https://api.example.com/conversations/{conversation}/messages \
  --header 'Content-Type: application/json' \
  --data '
{
  "message": "<string>",
  "parent_id": 123
}
'

{
  "id": 1,
  "type": "<string>",
  "conversationId": 123,
  "is_reply": true,
  "parent": null,
  "deleted": true,
  "message": "<string>",
  "date": 123,
  "edited_at": 123,
  "reactions": [
    {}
  ],
  "author": {
    "id": 1,
    "first_name": "John",
    "last_name": "Doe",
    "name": "John Doe",
    "title": "Manager",
    "active": true,
    "avatar": {},
    "archived_at": 123,
    "participant_type": "<string>",
    "subtext": "Manager - HQ (Sales)",
    "department": {
      "id": 10,
      "name": "Sales"
    },
    "unit": {
      "id": 5,
      "name": "HQ"
    }
  },
  "files": [
    {
      "id": 1,
      "name": "document.pdf",
      "mime": "application/pdf",
      "size": 102400,
      "type": "file",
      "extension": "pdf",
      "uploaded": true,
      "processing": false,
      "height": 123,
      "width": 123,
      "source": "<string>",
      "stream": "<string>",
      "versions": {},
      "screenshot": "<unknown>",
      "date": 123,
      "created_at": 123,
      "updated_at": 123,
      "created_formatted": "<string>",
      "updated_formatted": "<string>"
    }
  ],
  "voice": {
    "id": 1,
    "processing": true,
    "extension": "mp3",
    "duration": 12.5,
    "url": "<string>"
  }
}