How do i put a timer after a pause menu

Hello! Ive been traying to add a timer animation after a pause, i already have the animation of the timer but i dont really know how to make it pop up after the pause menu is closed plus ill like the game to be stoped while the animation is running and once the animations is over the game resumes.
Ill add the PauseMenu script.
using System.Collections;
using System.Collections.Generic;
using UnityEngine.SceneManagement;
using UnityEngine;

public class PauseMenu : MonoBehaviour
{
public static bool GameIsPaused = false;

public GameObject pauseMenuUI;




void Start()
{
GameIsPaused = false;
}

void Update ()
{
if(Input.GetKeyDown(KeyCode.Escape))
{
Cursor.lockState = CursorLockMode.None;
Cursor.visible = true;
if (GameIsPaused)
{
Resume();
}
else
{
Pause();
}
}
}

public void Resume ()
{
pauseMenuUI.SetActive(false);
Time.timeScale = 1f;
GameIsPaused = false;
}

void Pause()
{
pauseMenuUI.SetActive(true);
Time.timeScale = 0f;
GameIsPaused = true;
}

public void LoadOptionsMenu()
{
Time.timeScale = 0f;
SceneManager.LoadScene(0);
}

public void QuitGame()
{
Application.Quit();
Debug.Log("Quitting");
}

public void QuitToMainMenu()
{
Time.timeScale = 1f;
SceneManager.LoadScene(0);
}

public void TogglePause()
{
GameIsPaused = !GameIsPaused;
pauseMenuUI.SetActive(GameIsPaused);
Time.timeScale =GameIsPaused ? 0 : 1;
}


}