Unity Ads not Working???

I Don’t Really Know How To Explain It But I’ll Try.
When I Used An Advertisement Script And Tested It This Error Would Show up :


NullReferenceException: Object reference not set to an instance of an object
System.Net.AutoWebProxyScriptEngine.InitializeRegistryGlobalProxy () (at <525dc68fbe6640f483d9939a51075a29>:0)
System.Net.AutoWebProxyScriptEngine.GetWebProxyData () (at <525dc68fbe6640f483d9939a51075a29>:0)
System.Net.WebProxy.UnsafeUpdateFromRegistry () (at <525dc68fbe6640f483d9939a51075a29>:0)
System.Net.WebProxy…ctor (System.Boolean enableAutoproxy) (at <525dc68fbe6640f483d9939a51075a29>:0)
System.Net.WebProxy.CreateDefaultProxy () (at <525dc68fbe6640f483d9939a51075a29>:0)
System.Net.Configuration.DefaultProxySectionInternal.GetSystemWebProxy () (at <525dc68fbe6640f483d9939a51075a29>:0)
System.Net.Configuration.DefaultProxySectionInternal.GetDefaultProxy_UsingOldMonoCode () (at <525dc68fbe6640f483d9939a51075a29>:0)
System.Net.Configuration.DefaultProxySectionInternal.GetSection () (at <525dc68fbe6640f483d9939a51075a29>:0)
System.Net.WebRequest.get_InternalDefaultWebProxy () (at <525dc68fbe6640f483d9939a51075a29>:0)
System.Net.HttpWebRequest…ctor (System.Uri uri) (at <525dc68fbe6640f483d9939a51075a29>:0)
(wrapper remoting-invoke-with-check) System.Net.HttpWebRequest…ctor(System.Uri)
System.Net.HttpRequestCreator.Create (System.Uri uri) (at <525dc68fbe6640f483d9939a51075a29>:0)
System.Net.WebRequest.Create (System.Uri requestUri, System.Boolean useUriBase) (at <525dc68fbe6640f483d9939a51075a29>:0)
System.Net.WebRequest.Create (System.String requestUriString) (at <525dc68fbe6640f483d9939a51075a29>:0)
UnityEngine.Advertisements.Platform.Editor.EditorPlatform.Initialize (System.String gameId, System.Boolean testMode, System.Boolean enablePerPlacementLoad) (at Library/PackageCache/com.unity.ads@3.5.0/Runtime/Advertisement/Platform/Editor/EditorPlatform.cs:85)
UnityEngine.Advertisements.Platform.Platform.Initialize (System.String gameId, System.Boolean testMode, System.Boolean enablePerPlacementLoad) (at Library/PackageCache/com.unity.ads@3.5.0/Runtime/Advertisement/Platform/Platform.cs:64)
UnityEngine.Advertisements.Advertisement.Initialize (System.String gameId, System.Boolean testMode, System.Boolean enablePerPlacementLoad) (at Library/PackageCache/com.unity.ads@3.5.0/Runtime/Advertisement/Advertisement.cs:83)
UnityEngine.Advertisements.Advertisement.Initialize (System.String gameId, System.Boolean testMode) (at Library/PackageCache/com.unity.ads@3.5.0/Runtime/Advertisement/Advertisement.cs:67)
Test.Start () (at Assets/Scripts/Test.cs:29)


I Looked At Different Forums But Can’t Find The Answers, If You Need The Script Then Here :

using UnityEngine;
using UnityEngine.UI;
using UnityEngine.Advertisements;

[RequireComponent(typeof(Button))]
public class Test : MonoBehaviour, IUnityAdsListener {

    #if UNITY_ANDROID
    private string gameId = "3859891";
    #elif UNITY_EDITOR
    private string gameId = "3859891";
    #endif

    Button myButton;
    public string myPlacementId = "rewardedVideo";

    void Start()
    {
        myButton = GetComponent<Button>();

        // Set interactivity to be dependent on the Placement’s status:
        myButton.interactable = Advertisement.IsReady(myPlacementId);

        // Map the ShowRewardedVideo function to the button’s click listener:
        if (myButton) myButton.onClick.AddListener(ShowRewardedVideo);

        // Initialize the Ads listener and service:
        Advertisement.AddListener(this);
        Advertisement.Initialize(gameId, true);
    }

    // Implement a function for showing a rewarded video ad:
    void ShowRewardedVideo()
    {
        Advertisement.Show(myPlacementId);
    }

    // Implement IUnityAdsListener interface methods:
    public void OnUnityAdsReady(string placementId)
    {
        // If the ready Placement is rewarded, activate the button:
        if (placementId == myPlacementId)
        {
            myButton.interactable = true;
        }
    }

    public void OnUnityAdsDidFinish(string placementId, ShowResult showResult)
    {
        // Define conditional logic for each ad completion status:
        if (showResult == ShowResult.Finished)
        {
            // Reward the user for watching the ad to completion.
        }
        else if (showResult == ShowResult.Skipped)
        {
            // Do not reward the user for skipping the ad.
        }
        else if (showResult == ShowResult.Failed)
        {
            Debug.LogWarning("The ad did not finish due to an error.");
        }
    }

    public void OnUnityAdsDidError(string message)
    {
        // Log the error.
    }

    public void OnUnityAdsDidStart(string placementId)
    {
        // Optional actions to take when the end-users triggers an ad.
    }
}

Did you find the solution ???