Unity Ads Not Working (Not Displaying Ad)

I have a Ad Display script that will show a ad that you cant skip. It is set up so that the ad will be shown if a button is pressed but i doesn’t seem to be working

using UnityEngine;
using UnityEngine.Advertisements;
using System.Collections;

public class Ad_Display : MonoBehaviour {

	[SerializeField] string gameID = "1177323";

	void Awake ()
    {
        Advertisement.Initialize(gameID, true);
	}
	
	
	public void ShowAdd()
    {
        if (Advertisement.IsReady("rewardedVideoZone"))
        {
            ShowOptions options = new ShowOptions();
            options.resultCallback = HandleShowResult;
            Advertisement.Show("rewardedVideoZone", options);
            Debug.Log("Add has been Showen");
        }
    }

    private void HandleShowResult(ShowResult result)
    {
        switch (result)
        {
            case ShowResult.Finished:
                Debug.Log("The ad was successfully shown.");

                break;
            case ShowResult.Skipped:
                Debug.Log("The ad was skipped before reaching the end.");
                break;
            case ShowResult.Failed:
                Debug.LogError("The ad failed to be shown.");
                break;
        }
    }
}

Any help will be greatly appreciated.

See: Unity ads not showing rewarded video ad. - Questions & Answers - Unity Discussions