04-05 15:31:35.262 16547-16614/? E/Unity: NullReferenceException: Object reference not set to an instance of an object
                                            at AdManager.PlayRewardedAd (System.String scenario) [0x00000] in <filename unknown>:0
                                            at UnityEngine.Events.InvokableCall`1[System.String].Invoke (System.String args0) [0x00000] in <filename unknown>:0
                                            at UnityEngine.Events.CachedInvokableCall`1[System.String].Invoke (System.Object[] args) [0x00000] in <filename unknown>:0
                                            at UnityEngine.Events.UnityEvent.Invoke () [0x00000] in <filename unknown>:0
                                            at UnityEngine.UI.Button.Press () [0x00000] in <filename unknown>:0
                                            at UnityEngine.UI.Button.OnPointerClick (UnityEngine.EventSystems.PointerEventData eventData) [0x00000] in <filename unknown>:0
                                            at UnityEngine.EventSystems.ExecuteEvents.Execute (IPointerClickHandler handler, UnityEngine.EventSystems.BaseEventData eventData) [0x00000] in <filename unknown>:0
                                            at UnityEngine.EventSystems.ExecuteEvents.Execute[IPointerClickHandler] (UnityEngine.GameObject target, UnityEngine.EventSystems.BaseEventData eventData, Unity