аюсь использовать ионный 4 [email protected]

я слежу за этими слайдами:https://docs.google.com/presentation/d/1zlkmoSY4AzDJc_P4IqWLnzct41IqHyzGkLeyhlAxMDE/edit#slide=id.g282d0a7bfd_0_140

Я получаю эту ошибку: «TypeError: Невозможно прочитать свойство 'BaseClass' из null»

newlocation.page.html:

<ion-content>
  <h3>Ionic GoogleMaps Starter</h3>
  <div id="map_canvas">

  </div>
</ion-content>

newlocation.page.scss:

map_canvas {
  height: 90%;
}

newlocation.page.ts:

import { Component, OnInit } from '@angular/core';
import { Platform } from '@ionic/angular';
import { GoogleMaps, GoogleMap } from '@ionic-native/google-maps';


@Component({
  selector: 'app-newlocation',
  templateUrl: './newlocation.page.html',
  styleUrls: ['./newlocation.page.scss'],
})
export class NewlocationPage implements OnInit {

  map: GoogleMap;

  constructor(private platform: Platform) { }

  async ngOnInit() {
    await this.platform.ready();
    await this.loadMap();
  }

  loadMap() {
    this.map = GoogleMaps.create('map_canvas');
  }
}

package.json:

....
"@ionic-native/core": "5.0.0-beta.14",
"@ionic-native/google-maps": "^5.0.0-beta.20"
....
"cordova-plugin-googlemaps": {
        "API_KEY_FOR_ANDROID": (API-KEY),
        "PLAY_SERVICES_VERSION": "15.0.1",
        "ANDROID_SUPPORT_V4_VERSION": "27.+"
      }