Append your key and the token obtained from either Access/exchange-token or Access/impersonate to the querystring (key=mykey&token=kj123khb123hb123hb123jh123) or to the headers (Authorization:Bearer kj123khb123hb123hb123jh123) of your request.

{"message":"Updated message","subject":"Updated subject"}

{
  "result": "Comment Updated"
}