ionic admob free run android does not work

when I install admob free on ionic it does not run. play service error.

do not create apk no ionic cordova run andorid.

$ ionic cordova plugin add cordova-plugin-admob-free
$ npm install --save @ionic-native/admob-free

.

import { AdMobFree, AdMobFreeBannerConfig } from '@ionic-native/admob-free';


constructor(private admobFree: AdMobFree) { }


...


const bannerConfig: AdMobFreeBannerConfig = {
 // add your config here
 // for the sake of this example we will just use the test config
 isTesting: true,
 autoShow: true
};
this.admobFree.banner.config(bannerConfig);

this.admobFree.banner.prepare()
  .then(() => {
    // banner Ad is ready
    // if we set autoShow to false, then we will need to call the show method here
  })
  .catch(e => console.log(e));