Aktivate/Deactivate game object

I am trying to write a script for my mobile game (my first unity game) and I want to enable the “Dead” menu when the player is destroyed and that works fine, but when i want to disable it it does not work, hre is my code: (i know its messy)

 public class DeadMenu : MonoBehaviour
 {

public  GameObject deadMenu;

public void Retry()
{
    deadMenu.active = false;
    SceneManager.LoadScene("Game");
}
void Update() {
    if(Player.destroyed)
    {
        Appear();
    }    
}
public void Appear()
{
    deadMenu.active = true;
}
}

Hello, try :
deadMenu.SetActive(true);