How can i Implement iOS GameCenter leaderboards in my game?

Hello, I made a game for android and now I am trying to make it work with iOS. I have been following the documentation on how to use SocialPlatforms.GameCenter but Since i am fairly new at this I am getting stuck. :(

This is the Error I receive:

LeaderboardsController.cs(68,44): error CS1501: No overload for method ShowLeaderboardUI' takes 1' arguments

In my code I am passing ShowLeaderboardUI only one argument - a constant string which is my leaderboardID. (below is the entire class)

 using UnityEngine;
 using System.Collections;
 using UnityEngine.SocialPlatforms;
 using UnityEngine.SocialPlatforms.GameCenter;
 
 public class LeaderboardsController : MonoBehaviour
 {
 
     public static LeaderboardsController instance;
 
     private const string LEADERBOARDS_SCORE = "MYIDFORLEADERBOARDHERE";
 
     void Awake()
     {
         MakeSingleton();
     }
 
     void Start()
     {
         //PlayGamesPlatform.Activate();
 
     }
 
     void OnLevelWasLoaded()
     {
         ReportScore(GameController.instance.GetHighscore());
     }
 
     void MakeSingleton()
     {
         if(instance != null)
         {
             Destroy(gameObject);
         }else
         {
             instance = this;
             DontDestroyOnLoad(gameObject);
         }
     }
 
     public void AuthenticateToGameCenter()
     {
         //you are logged in
         #if UNITY_IPHONE
             Social.localUser.Authenticate((bool success) => {
               if(success)
               {
                 Debug.Log("Success");
               }
               else
               {
                 Debug.Log("Failed");
               }
             });
           #endif
     }
     public void OpenLeaderboardsScore()
     {
       #if UNITY_IPHONE
         if (Social.localUser.authenticated) {
                 GameCenterPlatform.ShowLeaderboardUI (LEADERBOARDS_SCORE);
             } else
             {
                 Debug.Log("something went wrong");
             }
         #endif
     }
 
     void ReportScore(int score)
     {
       #if UNITY_IPHONE
         if (Social.localUser.authenticated)
         {
             Social.ReportScore(score, LEADERBOARDS_SCORE, (bool success) => { });
         }
       #endif
     }
 }
 

The Docs say to have a TimeScope. I am not really sure how to write one - is this required?

Please help, thank you very much in advance! :)