photon pun custom propreties not working when doing a callback

hello im making a multiplayer game to play with my friends and im trying to make a button to set a ready state to player but i get this error

NullReferenceException: Object reference not set to an instance of an object SetReady.Ready () (at Assets/Scripts/SetReady.cs:24) Shoottest+<>c_DisplayClass6_0.b0 (UnityEngine.InputSystem.InputAction+CallbackContext ) (at Assets/Scripts/Shoottest.cs:29) UnityEngine.InputSystem.Utilities.DelegateHelpers.InvokeCallbacksSafe[TValue] (UnityEngine.InputSystem.Utilities.CallbackArray`1[System.Action`1[TValue]]& callbacks, TValue argument, System.String callbackName, System.Object context) (at Library/PackageCache/com.unity.inputsystem@1.2.0/InputSystem/Utilities/DelegateHelpers.cs:46) UnityEngine.InputSystem.LowLevel.<>c_DisplayClass7_0:b_0(NativeInputUpdateType, NativeInputEventBuffer) UnityEngineInternal.Input.NativeInputSystem:NotifyUpdate(NativeInputUpdateType, IntPtr)*

this is the code

 using System.Collections;
 
 using System.Collections.Generic;
 
 using UnityEngine;
 
 using Photon.Pun;
 
 using Hastable = ExitGames.Client.Photon.Hashtable;
 
 
 public class SetReady : MonoBehaviourPunCallbacks
 
 {
 
     public bool ReadyP;
 
     public Hastable hash;
 
     // Start is called before the first frame update
 
     void Start()
 
     {
 
        
 
     }
 
 
     // Update is called once per frame
 
     void Update()
 
     {
 
        
 
     }
 
     public void Ready()
 
     {
 
             bool Ready = (bool)PhotonNetwork.LocalPlayer.CustomProperties["Ready"];
 
             ReadyP = Ready;
 
             Ready = true;
 
             Hastable _hash = new Hastable();
 
             hash = _hash;
 
             _hash.Add("Ready", Ready);
 
             PhotonNetwork.LocalPlayer.SetCustomProperties(_hash);
 
     }
 
 }

why it does this?