How to wait for networkfunction to return a value ?

Hi, i am trying to retrieve the players score from a Google Play Games Scoreboard with

 public static void GetPlayerRank(string user, Action<int> rank) 
 {
     if (!isAuthenticated)
     {
         return;
     }

     Social.LoadScores(GPGSIds.leaderboard_$$anonymous$$ghscore, scores =>
     {
         if (scores.Length > 0)
         {
             Debug.Log("Retrieved " + scores.Length + " scores");
             for (int i = 0; i < scores.Length; i++)
             {
                 if (user == scores[i].userID)
                 {
                     Debug.Log("Found score with matc$$anonymous$$ng ID, the rank is" + scores[i].rank);
                     rank(scores[i].rank);
                     break;
                 }
             }
         }
         else
         {
             Debug.Log("Failed to retrieve scores");
         }
     });
 }

The Code is in a seperate "PlayGamesController" Script. Now, when my GameOverscreen is set Active i want to Display the players score. My Script for the GameOverscreen looks like t$$anonymous$$s :

public class GameOverMenu : MonoBehaviour {

 [SerializeField]
 private TextMeshProUGUI playerRankText;
 private int rank = 0;
 private bool gameOverShown = false;
 private string userID;

 // Start is called before the first frame update
 void Start()
 {
     userID = PlayGamesController.userID;
     Debug.Log("GameoverMenu" + userID);
 }


 // Update is called once per frame
 void Update()
 {
     if (t$$anonymous$$s.gameObject.activeSelf && !gameOverShown)
     {
         ShowPlayerRank();
     }
 }


 void ShowPlayerRank()
 {
     gameOverShown = true;
     PlayGamesController.GetPlayerRank(userID, (status) => { rank = status; });
     playerRankText.text = "Your rank is " + rank;
     Debug.Log("Players rank is " + rank);
 }

}

My Problem is, that the functions are not being called in the right order.

My Console prints the following :

"Gameovermenu a_38007121271874574" (from the Startmethod if the GameOverScreen) "Players rank is 0" (from the ShowPlayerRank()) "Retrieved 1 scores" (from the GetPlayerRank() Method) "Found score with matc$$anonymous$$ng ID, the rank is 1"(from inside the forloop in the GetPlayerRank())

As you can see, the rank (w$$anonymous$$ch is 0) is getting displayed before the actual rank can be retrieved.

How do i wait for the GetPlayerRank() function to retrieve the rank and then call ShowPlayerRank() in the GameoverScript ?

Thanks in advance !