How to Activate UI in an Array Using C#

I am making this game where you have 30 seconds to do something. If you do not do the required task it will display a game over menu (not another scene) but it will Display the menu as soon as the game starts, instead of displaying it after the timer is up.

Here Is My Script:

 public float Timer = 30f;
 private Text timerText;


 public GameObject[] componentsToActivate;



 void Start()
 {

     Timer = 30;
     timerText = GetComponent<Text>();


 }

 // Update is called once per frame
 void Update()
 {
     Timer -= Time.deltaTime;
     timerText.text = Timer.ToString("f0");
     print(Timer);

     if (Timer >= 0)
     {
         activateComponents();
     }
 }

 void activateComponents()
 {
     GameObject[] allObjects = UnityEngine.GameObject.FindGameObjectsWithTag("GameOverMenu");

     foreach (GameObject Obj in componenetsToDisable)
     {
         Obj.SetActive(true);
     }
 }

}