I’ve been able to make a countdown timer for my game but have been unable to set it up so that when the timer ends/ hits zero, it switches to a game over scene.
Here’s the time script that I’m working with:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
public class Countdown : MonoBehaviour
{
public float timeStart = 60;
public Text textBox;
void Start()
{
textBox.text = timeStart.ToString();
}
void Update()
{
timeStart -= Time.deltaTime;
textBox.text = Mathf.Round(timeStart).ToString();
}
}
Help would be much appreciated 
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.SceneManagement;
public class Countdown : MonoBehaviour
{
[SerializeField] int timeOnStart = 60;
[SerializeField] Text textBox;
[SerializeField] string sceneName = "> scene name goes here <";
int _counter;
void OnEnable()
{
textBox.text = $"Time Left: --";
ClockStart();
}
void OnDisable ()
{
ClockStop();
}
public void ClockStart ()
{
_counter = timeOnStart;
UpdateText();
InvokeRepeating(
nameof(ClockTick) ,
1f ,// the very first tick after 1 second
1f// 1 second between every tick
);
}
public void ClockStop ()
{
CancelInvoke( nameof(ClockTick) );
}
void ClockTick ()
{
_counter--;
UpdateText();
if( _counter<=0 )
{
ClockStop();
SceneManager.LoadScene( sceneName );
}
}
void UpdateText ()
{
textBox.text = $"Time Left: {Mathf.Round(_counter)}";
}
}