ads offline

hi everyone i'm new to the forum and i hope to find solution to my problem
I started the development of a small VR application on the unit below all goes well but wanting to integrate an ads that is provided in service I made a scene that serves as a splash screen I also makes a little code that allows me to display ads switcher for another scene but also no problem but once I disconnect from the Internet The application remains stuck on the splash screen
this is the code

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3. using UnityEngine.SceneManagement;
4. using UnityEngine.Advertisements;
5.  
6. public class SimpleAds : MonoBehaviour
7. {
8.     void Start ()
9.     {
10.         Advertisement.Initialize ("33675", true);
11.  
12.         StartCoroutine (ShowAdWhenReady());
13.     }
14.  
15.     IEnumerator ShowAdWhenReady()
16.     {
17.         while (!Advertisement.IsReady())
18.             yield return null;
19.  
20.         Advertisement.Show ();
21.  
22.  
23.         StartCoroutine("Wait");
24.         }
25.  
26.         IEnumerator Wait()
27.         {
28.             yield return new WaitForSeconds(1);
29.  
30.         SceneManager.LoadScene(1);
31.     }
32.  
33.  
34. }

 

this is because unity ads is a server full of ads that need a network to work