Adtapsy help

I’ve integrated Adtapsy into my game and enabled testmode yet I do not get any adverts?
Has anyone got a full detailed explanation on how to integrate it not including the one provided by Adtapsy
This is my Adscript:

using UnityEngine;

public class Adverts : MonoBehaviour
{
    public static Adverts manager;

    void Awake()
    {
        manager = this;
    }

    void Start()
    {
        AdTapsy.SetTestMode(true, "Simulator", "xxxxxxxxxxxxxxxxx");

        AdTapsy.OnAdClicked += delegate (int zoneId)
        {
            if (zoneId == AdTapsy.InterstitialZone)
            {
                ClickCounter.manager.SeenAdReady4New();
            }
        };
        AdTapsy.OnAdSkipped += delegate (int zoneId)
        {
            if (zoneId == AdTapsy.InterstitialZone)
            {
                ClickCounter.manager.Ready4Ad();
            }
        };
        AdTapsy.OnAdFailedToShow += delegate (int zoneId)
        {
            if (zoneId == AdTapsy.InterstitialZone)
            {
                ClickCounter.manager.Failed2ShowAd();
            }
        };
    }

    public void ShowInterstitial()
    {
        if (AdTapsy.IsInterstitialReadyToShow())
        {
            AdTapsy.ShowInterstitial();
        }
    }

}

You need to start Adtapsy session.

void Start (){
//Setting callbacks
//Setting testmode

//Depending which plattform you are using

AdTapsy.StartSessionAndroid ("App_ID");
AdTapsy.StartSessionIOS ("App_ID");

}