Admobpro createBanner Object(...) is not a function

I’m trying to use ionic cordova-admob-pro

error page
TypeError: Object(…) is not a function
at AdMobPro.createBanner (http://localhost:8100/build/vendor.js:74995:140)

import { AdMobPro } from ‘@ionic-native/admob-pro/ngx’;
import { IonicPage, NavController, NavParams, AlertController, Platform } from ‘ionic-angular’;

constructor(public navCtrl: NavController, public navParams: NavParams,private userservice:UserService,private afDatabase:AngularFireDatabase,private imageLoaderConfig: ImageLoaderConfig, public alertCtrl: AlertController
,private admob: AdMobPro,private util:UtilService,private platform: Platform)

ionViewDidEnter() {
this.banner();
}

banner() {
let adId;
if (this.platform.is(‘android’)) {
adId = this.util.adMobId.android.banner;
} else if (this.platform.is(‘ios’)) {
adId = this.util.adMobId.ios.banner;
}
this.admob.createBanner({
adId: adId,
isTesting: true // remove in production
})
.then(() => {
this.admob.showBanner(this.admob.AD_POSITION.BOTTOM_CENTER);
})
.catch((err) => {
console.log(err);
});
}