This will be a POST request sent to /api/cards/{cardId}/comments with a payload similar to the following:

{
  "comment": "This is a test comment."
}

The response of the API will be similar to the following when it succeeds:

{
  "id": 1,
  "detail": "{"comment":"This is a test comment."}",
  "type": "add-comment",
  "userId": 1,
  "cardId": 4,
  "boardId": 1,
  "createdDate": 1538239135000
}