Parse save always error

        Parse.initialize(ApiKeys.appId, ApiKeys.jsKey, ApiKeys.masterKey);
        function submit(){
            var GameScore = Parse.Object.extend("GameScore");
            var gameScore = new GameScore();

            gameScore.save({
              score: 1337,
              playerName: "Sean Plott",
              cheatMode: false
            }, {
              success: function(gameScore) {
                // The object was saved successfully.
                debug_log("score success");
              },
              error: function(gameScore, error) {
                // The save failed.
                // error is a Parse.Error with an error code and message.
                debug_log("score error");
              }
            });
       }

I am sure that I have already config the keys. But I still cannot save, everytime, when I submit, it give me back error.

I use back{4}app instead of parse, is there something important was ignored by me?

Thanks in advance.

Add Parse.serverURL="back4app api URL" Solve the ptoblem.