This is the script for the escape menu.

EscapeMenu.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
//We import Unity UI, but we also import something else!
using UnityEngine.UI;
using UnityEngine.SceneManagement;
public class EscapeMenu : MonoBehaviour
{
    public KeyCode EscapeKey;
    private bool EscapeMenuUp;
    public Canvas EscapeMenuCanvas;
    void Start(){
        EscapeMenuUp=false;
        EscapeMenuCanvas.enabled = false;
    }
    void LateUpdate(){
        
        if(Input.GetKeyUp(EscapeKey)){
            if(EscapeMenuUp == false){
                EscapeMenuCanvas.enabled = true;
                EscapeMenuUp = !EscapeMenuUp;
            }
            else if(EscapeMenuUp == true){
                EscapeMenuCanvas.enabled = false;
                EscapeMenuUp = !EscapeMenuUp;
            }
        }

    }

    public void OnMainMenuButton(){
        SceneManager.LoadScene(0);
    }
    public void onQuitButton(){
        Application.Quit();
    }
}