Ionic 2 Admob class not found how can i fix this =?

constructor(public navCtrl: NavController,
public navParams: NavParams,
public storage : NativeStorage,
public http: Http,
public alert : AlertController,
private translateService: TranslateService,
public platform : Platform,
public admob : AdMobPro) {
platform.ready().then(() => {
var admobid = {
banner: ‘xxxxxxxxxxxx’,
interstitial: ‘xxxxxxxxxxxxxxxxxx’
};

          this.admob.createBanner({
              adId: admobid.banner,
              isTesting: true,
              autoShow: true,
              position: this.admob.AD_POSITION.BOTTOM_CENTER
          })



          this.admob.prepareInterstitial({
              adId: admobid.interstitial,
              isTesting: true,
              autoShow: false
          })
      });