first steps with facebook sdk - print name in GUI

hello everyone, I'm trying to understand the use of the SDK in facebook unity. What I want to do is retrieve the name of a user and print them using a gui label. The process works well but I do not know how I can print it in the GUI

 using UnityEngine;
 using System.Collections;
 using System;
 using System.Collections.Generic;
 
 public class init : MonoBehaviour
 {
     bool isInit = false;
     string hasPerm = "***";
 
     private void CallFBInit()
     {
         FB.Init(OnInitComplete, OnHideUnity);
 
     }
     void OnGUI()
     {
         if (GUI.Button (new Rect (10, 10, 300, 100), "InitInit: " + isInit))
             CallFBInit ();
         
         if (GUI.Button (new Rect (10, 110, 300, 100), "LogIn - Logged: " + FB.IsLoggedIn)) {
                         CallFBLogin ();
 
 
                 print ("NOME"+FB.UserId +"/first_name");
             
                 }
         if (GUI.Button (new Rect (10, 210, 300, 100), "Permission - friends: " + hasPerm)) {
                         CallPermissionCheck ();
 
              
                 }
     }
     
 
     
     private void OnInitComplete()
     {
         Debug.Log("FB.Init completed: Is user logged in? " + FB.IsLoggedIn);
         isInit = true;
     }
     
     private void OnHideUnity(bool isGameShown)
     {
         Debug.Log("Is game showing? " + isGameShown);
     }
     
     private void CallFBLogin()
     {
         FB.Login("publish_actions, user_friends", LoginCallback);
 
     }
     
     void LoginCallback(FBResult result)
     {
         string lastResponse;
         
         if (result.Error != null)
             lastResponse = "Error Response:\n" + result.Error;
         else if (!FB.IsLoggedIn)
         {
             lastResponse = "Login cancelled by Player";
         }
         else
         {
             lastResponse = "Login was successful!";
         }
         
         Debug.Log("lastResponse: "+lastResponse);
     }
     
     void CallPermissionCheck()
     {
         FB.API("/me/permissions", Facebook.HttpMethod.GET, PermissionCallback);
 
     }
     
     void PermissionCallback(FBResult result)
     {
         if (!String.IsNullOrEmpty(result.Error))
         {
             Debug.Log("Error Response:\n" + result.Error);
         }
         else
         {
             Debug.Log("Get user's permissions was successful!");
             Debug.Log ("Result: "+result.Text);
             
             
             var permissionDict = Facebook.MiniJSON.Json.Deserialize(result.Text) as Dictionary<string, object>;
             IDictionary persmissionData = permissionDict;
             foreach(IDictionary perm in (List<object>)persmissionData["data"])
             {
                 if((string)perm["permission"] == "user_friends")
                 {
                     hasPerm = (string)perm["status"];
                     
                     // This will deauthorise the permissions for the user and then log them out
                     /*
                      if(hasPerm != "granted")
                      {
                          FB.API ("me/permissions", Facebook.HttpMethod.DELETE, RemovePermissionCallback);
                          FB.Logout();
                      }
                      */
                     FB.API("me?fields=name", Facebook.HttpMethod.GET, NameCallBack);
 
                 }
             }
             
         }
     }
     
     void RemovePermissionCallback(FBResult result)
     {
         if (!String.IsNullOrEmpty(result.Error))
         {
             Debug.Log("Error Response:\n" + result.Error);
         }
         else
         {
             Debug.Log("RemovePermissionCallback was successful!");
             Debug.Log ("Result: "+result.Text);
         }
     }
 
     void NameCallBack(FBResult result)
     {
         IDictionary dict = Facebook.MiniJSON.Json.Deserialize(result.Text) as IDictionary;
         string fbname = dict["name"].ToString();
 
 
     }
     
 }