Android android ADMOB cant load ads

[3jgamesdev]

Hi good day,

I just follow what is written here in the documentation, but still it wont load my ads and im having an error while loading the ads,
this is my code

Create event:

if os_type == os_android
    {
    app_id = "ca-app-pub-9788304447904432~8732328925";
    banner_id = "ca-app-pub-9788304447904432~8732328925";
    interstitial_id = "ca-app-pub-9788304447904432/2491683197";
    //rewarded_id = "ca-app-pub-4337965814269841/5893055399";
    }

GoogleMobileAds_Init(interstitial_id, app_id);
GoogleMobileAds_LoadInterstitial();
interstitial_loaded = false;

Async Social:

var _id = async_load[? "id"];
if _id == GoogleMobileAds_ASyncEvent
{
var ident = async_load[? "type"];
switch (ident)
    {
    case "banner_load":
        if async_load[? "loaded"] == 1
            {
            var _bw = GoogleMobileAds_BannerGetWidth();
            var _bh = GoogleMobileAds_BannerGetHeight();
            var _hh = display_get_height();
            var _ww = display_get_width();
            GoogleMobileAds_MoveBanner((_ww / 2) - (_bw / 2), _hh - _bh);
            }
        break;
    }
}

Step event:

GoogleMobileAds_AddBannerAt(banner_id, GoogleMobileAds_Banner, camera_get_view_x(0),camera_get_view_y(0));

Please help i still didnt get where i went wrong