curl -X POST \
 /invoices/{id}/comment \
 --header "Content-Type: application/json" \
 --header "Authorization: Bearer <token>" \
 --data '{
    "comment": ""
}'

{
  "id": "<string>",
  "dateTime": "2023-11-07T05:31:56Z",
  "type": "commented",
  "user": {
    "user": {
      "firstName": "John",
      "lastName": "Doe",
      "email": "jsmith@example.com"
    },
    "deactivated": true,
    "avatar": "<string>",
    "fullName": "<string>",
    "initial": "<string>",
    "gravatarUrl": "<string>"
  },
  "metadata": {},
  "pinned": true
}