google play leaderboards help?

hello,

I am new to social media integration and I have built an entire game in unity JS. I am trying to send a score to the leaderboard with a JS script using the following code:

 #pragma strict
 import GooglePlayGames;
 import UnityEngine.SocialPlatforms;
 
 function Update () {
 if ( game.score > game.highscore ){
     game.highscore = game.score;
     PlayerPrefs.SetInt("game.highscore", game.score);
     Social.ReportScore(game.highscore, "leaderboard ID", (sucess : boolean) => {
         // handle success or failure
         Debug.Log ("posted");
     });
     }
 else {game.highscore = game.highscore;}
 }

This is creating a few errors - (9,70): BCE0044: expecting ), found ':', and also (9,72): BCE0044: expecting ), found 'boolean'.

can anyone help me with this implementation in JS? Any help will be greatly appreciated.