Why Google Maps Cordova ionic angular, only working in Android and blank in IOS?

**I'm submitting a ...** (check one with "x")
- [ ] question
- [ x] any problem or bug report
- [ ] feature request

**If you choose 'problem or bug report', please select OS:** (check one with "x")
- [ ] **Android**
- [ x] **iOS**
- [ ] **Browser**

**cordova information:** (run `$> ionic cordova plugin list`)

```
com-badrit-base64 0.2.0 "Base64"
com.googlemaps.ios 3.8.0 "Google Maps SDK for iOS"
cordova-android-play-services-gradle-release 4.0.0 "cordova-android-play-services-gradle-release"
cordova-androidx-build 1.0.3 "cordova-androidx-build"
cordova-plugin-androidx 2.0.0 "cordova-plugin-androidx"
cordova-plugin-background-geolocation 3.1.0 "CDVBackgroundGeolocation"
cordova-plugin-camera 4.1.0 "Camera"
cordova-plugin-datepicker 0.9.3 "DatePicker"
cordova-plugin-device 2.0.2 "Device"
cordova-plugin-document-viewer 0.9.13 "SitewaertsDocumentViewer"
cordova-plugin-fcm-with-dependecy-updated 6.3.1 "Cordova FCM Push Plugin"
cordova-plugin-file 6.0.2 "File"
cordova-plugin-file-transfer 1.7.1 "File Transfer"
cordova-plugin-filepath 1.5.8 "cordova-plugin-filepath"
cordova-plugin-geolocation 4.0.2 "Geolocation"
cordova-plugin-globalization 1.11.0 "Globalization"
cordova-plugin-googlemaps 2.8.0-20200601-1013 "cordova-plugin-googlemaps"
cordova-plugin-ionic-keyboard 2.2.0 "cordova-plugin-ionic-keyboard"
cordova-plugin-ionic-webview 5.0.0 "cordova-plugin-ionic-webview"
cordova-plugin-iroot 0.8.1 "iRoot"
cordova-plugin-nativegeocoder 3.4.0 "NativeGeocoder"
cordova-plugin-network-information 2.0.2 "Network Information"
cordova-plugin-screen-orientation 3.0.2 "Screen Orientation"
cordova-plugin-splashscreen 5.0.2 "Splashscreen"
cordova-plugin-statusbar 3.0.0-dev "StatusBar"
cordova-plugin-vibration 3.1.1 "Vibration"
cordova-plugin-whitelist 1.3.3 "Whitelist"
es6-promise-plugin 4.2.2 "Promise"
```

**package.json information:**
```
"@ionic-native/core": "^5.22.0-beta-1",
"@ionic-native/google-maps": "^5.5.0",
"cordova-plugin-googlemaps": "git+https://github.com/mapsplugin/cordova-plugin-googlemaps.git#multiple_maps",
"cordova-plugin-googlemaps-sdk": "git+https://github.com/mapsplugin/cordova-plugin-googlemaps-sdk.git",
```

**Current behavior:**
Google Maps is blank but it shows Google logo, Everything normal in Android.

I have added this line in config.xml :
````

````

Also, i've enable Google Maps for IOS and restrict with my bundle id (com.xxxxx.hris) as well.
Here the restrict information :
````
Maps SDK for iOS
Geocoding API
Geolocation API
Maps SDK for Android
Places API
Maps Static API
````

**Expected behavior:**
It should be running fine like Android

**Screen capture:**
[Android]

[iOS]

Bắt đầu bằng cách xem xét preference GOOGLE_MAPS_IOS_API_KEY trong config.xml và các phiên bản plugin trong package.json, sau đó chạy lệnh ionic cordova plugin list được liệt kê cho thiết lập iOS. Xác minh API key của iOS và các hạn chế của bundle-ID dựa trên hiện tượng bản đồ trống. Hoàn tất nghĩa là bản đồ được render trên iOS thay vì chỉ hiển thị logo Google.

Do mô hình lập chỉ mục viết ra từ nội dung của issue.