Admob does not work on real devices


#1

​I find an app cannot show ad banner on apk release version, but it works fine on testing version in Android emulator. When I tried to build an apk, and test it on a real devices, it does not show anything.
details as follow:
cli packages: (/usr/local/lib/node_modules)

@ionic/cli-utils  : 1.12.0

ionic (Ionic CLI) : 3.12.0

global packages:

cordova (Cordova CLI) : 7.1.0 

local packages:

@ionic/app-scripts : 3.0.0

Cordova Platforms  : android 6.3.0

Ionic Framework    : ionic-angular 3.7.1

System:

ios-deploy : 1.9.1 

Node       : v6.9.5

npm        : 4.3.0 

OS         : macOS Sierra

Xcode      : Xcode 9.0 Build version 9A235 

Misc:

backend : pro

$ ionic cordova plugin add cordova-plugin-admobpro
$ npm install --save @ionic-native/admob-pro
already run.

home.ts
import { Component } from ‘@angular/core’;
import { NavController } from ‘ionic-angular’;
import { AdMobPro } from ‘@ionic-native/admob-pro’;
@Component({
selector: ‘page-home’,
templateUrl: ‘home.html’
})
export class HomePage {

constructor(public navCtrl: NavController,private admob: AdMobPro) {
this.banner();
}

onClick() {
let adId = ‘ca-app-pub-xxxxx’;

this.admob.prepareInterstitial({adId: adId})
.then(() => { this.admob.showInterstitial(); });
}

banner(){
let adId = ‘ca-app-pub-xxxxxx’;

if(this.admob) this.admob.createBanner({
adId: ‘ca-app-pub-xxxxx’,
position: this.admob.AD_POSITION.BOTTOM_CENTER,
autoShow: true });

Please help, many thanks.