How can ı activate my gameobject after wait little bit ?

Unity Engine
1

I created a panel for my game over scene. I want to activate after one player reaches 3 in scoreboard. Problem is my panel is not showing. What is wrong about this script ? Thanks for help.

public float speed;
    public Text countText;
    public Text winText;
public GameObject panel;

    private float t;

    // Create private references to the rigidbody component on the player, and the count of pick up objects picked up so far
    private Rigidbody rb;
    private int count;

    // At the start of the game..
    void Start()
    {
      // Make the game run as fast as possible

        // Assign the Rigidbody component to our private rb variable
        rb = GetComponent<Rigidbody>();

        // Set the count to zero
        count = 0;

        // Run the SetCountText function to update the UI (see below)
        SetCountText();

        // Set the text property of our Win Text UI to an empty string, making the 'You Win' (game over message) blank
        winText.text = "";
    }

    // Each physics step..
    void FixedUpdate()
    {
        // Set some local float variables equal to the value of our Horizontal and Vertical Inputs
        float moveHorizontal = Input.GetAxis("Horizontal");
        float moveVertical = Input.GetAxis("Vertical");


        // Create a Vector3 variable, and assign X and Z to feature our horizontal and vertical float variables above
        Vector3 movement = new Vector3(moveHorizontal, 0.0f, moveVertical);

        // Add a physical force to our Player rigidbody using our 'movement' Vector3 above,
        // multiplying it by 'speed' - our public player speed that appears in the inspector
        rb.AddForce(movement * speed);
    }

    // When this game object intersects a collider with 'is trigger' checked,
    // store a reference to that collider in a variable named 'other'..
    void OnTriggerEnter(Collider other)
    {
        // ..and if the game object we intersect has the tag 'Pick Up' assigned to it..
        if (other.gameObject.CompareTag("Pick Up"))
        {

            // Make the other game object (the pick up) inactive, to make it disappear
            other.gameObject.SetActive(true);

            // Add one to the score variable 'count'
            count = count + 1;

            // Run the 'SetCountText()' function (see below)
            SetCountText();
        }
    }

    // Create a standalone function that can update the 'countText' UI and check if the required amount to win has been achieved
    void SetCountText()
    {
        // Update the text field of our 'countText' variable
        countText.text = ": " + count.ToString();

        // Check if our 'count' is equal to or exceeded 12
        if (count >= 3)
        {
            {
                // Set the text value of our 'winText'
                winText.text ="WİNNER!";

                {
                    StartCoroutine(WaitForIt(2.1F));
                }
                IEnumerator WaitForIt(float waitTime)
                {
                    yield return new WaitForSeconds(waitTime);

        gameObject.SetActive(true);
                }

                {

                }
2

Okey ı solved. I just added panel. “panel.gameObject.SetActive(true);”