Admob Rewarded Video third party

Question

I have been trying my best to get the Admob Rewarded Video to work/show in my app, but I just can't get it to work. I have all the plugins installed correctly I believe.

This is my current code.

using UnityEngine;
using System.Collections;
using GoogleMobileAds.Api;



public class AdManager2 : MonoBehaviour
{
    string adUnitId = "MY_UNIT_ID";
    RewardBasedVideoAd rewardBasedVideo = null;

    void Start()
    {
        rewardBasedVideo = RewardBasedVideoAd.Instance;
    }

    public void adButton()
    {
        AdRequest request = new AdRequest.Builder().Build();
        rewardBasedVideo.LoadAd(request, adUnitId);
        showAd();
    }

    public void showAd()
    {
        if (rewardBasedVideo.IsLoaded())
        {
            rewardBasedVideo.Show();
        }
    }
}

This doesn't work for me, I click the button but nothing works. I have also tried multiple scripts from different people too, but not a single one of them work for me...

I would really appreciate it if someone could help me with this, Thanks in advance,

-Lente