How to download assetbundles and use it locally in unity 3d 2018?

I want to download asset bundles (Windows and android )by checking the version first and if there is a new version the game download it automatically and uses it locally after this ? all i have done until now is to download the asset bundle only , here is my code : using UnityEngine; using UnityEngine.Networking; using UnityEngine.SceneManagement;

 public class loader : MonoBehaviour
 {
 private AssetBundleCreateRequest bundleRequest;
 private UnityWebRequest request;
 
 private void Start()
 {
 
           request = UnityWebRequestAssetBundle.GetAssetBundle("http://localhost/focus/level2",1);
     request.SendWebRequest();
 }
 
 private void Update()
 {
     if (request.isDone)
     {
         AssetBundle bundle = DownloadHandlerAssetBundle.GetContent(request);
 
         SceneManager.LoadScene("SampleScene");
     }
     else
     {
         Debug.Log("not");
     }
 }
 }