Invoke() does not delay my game timer

I have problem with my timer. Invoke() should delay the GameTimer() but timer still runs at the start of the game, it just doesn't show up after the Invoke() is done. I want the timer to start after Invoke, is there a way?

     public Text timerText;
     private float startTime;
     private bool finnish = false;
     
     // Update is called once per frame
     void Update () {
 
         if (finnish)
             return;
 
         Invoke ("GameTimer", 2.0f);
     }
 
     void GameTimer () {
         
         float t = Time.time - startTime;
 
         string minutes = ((int)t / 60).ToString ();
         string seconds = (t % 60).ToString ("f2");
 
         timerText.text = minutes + ":" + seconds;
     }