diff --git a/flutter_inappwebview_android/android/src/main/java/com/pichillilorenzo/flutter_inappwebview_android/InAppWebViewFlutterPlugin.java b/flutter_inappwebview_android/android/src/main/java/com/pichillilorenzo/flutter_inappwebview_android/InAppWebViewFlutterPlugin.java
index b475a0e3d7..0ca035daad 100755
--- a/flutter_inappwebview_android/android/src/main/java/com/pichillilorenzo/flutter_inappwebview_android/InAppWebViewFlutterPlugin.java
+++ b/flutter_inappwebview_android/android/src/main/java/com/pichillilorenzo/flutter_inappwebview_android/InAppWebViewFlutterPlugin.java
@@ -24,9 +24,7 @@
 import io.flutter.embedding.engine.plugins.activity.ActivityAware;
 import io.flutter.embedding.engine.plugins.activity.ActivityPluginBinding;
 import io.flutter.plugin.common.BinaryMessenger;
-import io.flutter.plugin.common.PluginRegistry;
 import io.flutter.plugin.platform.PlatformViewRegistry;
-import io.flutter.view.FlutterView;
 
 public class InAppWebViewFlutterPlugin implements FlutterPlugin, ActivityAware {
 
@@ -64,51 +62,27 @@ public class InAppWebViewFlutterPlugin implements FlutterPlugin, ActivityAware {
   public ProcessGlobalConfigManager processGlobalConfigManager;
   public FlutterWebViewFactory flutterWebViewFactory;
   public Context applicationContext;
-  public PluginRegistry.Registrar registrar;
   public BinaryMessenger messenger;
   public FlutterPlugin.FlutterAssets flutterAssets;
   @Nullable
   public ActivityPluginBinding activityPluginBinding;
   @Nullable
   public Activity activity;
-  @SuppressWarnings("deprecation")
-  public FlutterView flutterView;
 
   public InAppWebViewFlutterPlugin() {}
 
-  @SuppressWarnings("deprecation")
-  public static void registerWith(PluginRegistry.Registrar registrar) {
-    final InAppWebViewFlutterPlugin instance = new InAppWebViewFlutterPlugin();
-    instance.registrar = registrar;
-    instance.onAttachedToEngine(
-            registrar.context(), registrar.messenger(), registrar.activity(), registrar.platformViewRegistry(), registrar.view());
-  }
-
   @Override
-  public void onAttachedToEngine(FlutterPluginBinding binding) {
+  public void onAttachedToEngine(@NonNull FlutterPluginBinding binding) {
     this.flutterAssets = binding.getFlutterAssets();
-
-    // Shared.activity could be null or not.
-    // It depends on who is called first between onAttachedToEngine event and onAttachedToActivity event.
-    //
-    // See https://github.com/pichillilorenzo/flutter_inappwebview/issues/390#issuecomment-647039084
-    onAttachedToEngine(
-            binding.getApplicationContext(), binding.getBinaryMessenger(), this.activity, binding.getPlatformViewRegistry(), null);
-  }
-
-  @SuppressWarnings("deprecation")
-  private void onAttachedToEngine(Context applicationContext, BinaryMessenger messenger, Activity activity, PlatformViewRegistry platformViewRegistry, FlutterView flutterView) {
-    this.applicationContext = applicationContext;
-    this.activity = activity;
-    this.messenger = messenger;
-    this.flutterView = flutterView;
+    this.applicationContext = binding.getApplicationContext();
+    this.messenger = binding.getBinaryMessenger();
 
     inAppBrowserManager = new InAppBrowserManager(this);
     headlessInAppWebViewManager = new HeadlessInAppWebViewManager(this);
     chromeSafariBrowserManager = new ChromeSafariBrowserManager(this);
     noHistoryCustomTabsActivityCallbacks = new NoHistoryCustomTabsActivityCallbacks(this);
     flutterWebViewFactory = new FlutterWebViewFactory(this);
-    platformViewRegistry.registerViewFactory(
+    binding.getPlatformViewRegistry().registerViewFactory(
             FlutterWebViewFactory.VIEW_TYPE_ID, flutterWebViewFactory);
 
     platformUtil = new PlatformUtil(this);
@@ -132,6 +106,10 @@ private void onAttachedToEngine(Context applicationContext, BinaryMessenger mess
 
   @Override
   public void onDetachedFromEngine(@NonNull FlutterPluginBinding binding) {
+    disposeManagers();
+  }
+
+  private void disposeManagers() {
     if (platformUtil != null) {
       platformUtil.dispose();
       platformUtil = null;
@@ -198,38 +176,21 @@ public void onDetachedFromEngine(@NonNull FlutterPluginBinding binding) {
   public void onAttachedToActivity(ActivityPluginBinding activityPluginBinding) {
     this.activityPluginBinding = activityPluginBinding;
     this.activity = activityPluginBinding.getActivity();
-
-    if (noHistoryCustomTabsActivityCallbacks != null) {
-      this.activity.getApplication().registerActivityLifecycleCallbacks(noHistoryCustomTabsActivityCallbacks.activityLifecycleCallbacks);
-    }
   }
 
   @Override
   public void onDetachedFromActivityForConfigChanges() {
-    if (activity != null && noHistoryCustomTabsActivityCallbacks != null) {
-      this.activity.getApplication().unregisterActivityLifecycleCallbacks(noHistoryCustomTabsActivityCallbacks.activityLifecycleCallbacks);
-    }
-
     activityPluginBinding = null;
     activity = null;
   }
 
   @Override
   public void onReattachedToActivityForConfigChanges(ActivityPluginBinding activityPluginBinding) {
-    this.activityPluginBinding = activityPluginBinding;
-    this.activity = activityPluginBinding.getActivity();
-
-    if (noHistoryCustomTabsActivityCallbacks != null) {
-      this.activity.getApplication().registerActivityLifecycleCallbacks(noHistoryCustomTabsActivityCallbacks.activityLifecycleCallbacks);
-    }
+    onAttachedToActivity(activityPluginBinding);
   }
 
   @Override
   public void onDetachedFromActivity() {
-    if (activity != null && noHistoryCustomTabsActivityCallbacks != null) {
-      this.activity.getApplication().unregisterActivityLifecycleCallbacks(noHistoryCustomTabsActivityCallbacks.activityLifecycleCallbacks);
-    }
-
     activityPluginBinding = null;
     activity = null;
   }
diff --git a/flutter_inappwebview_android/android/src/main/java/com/pichillilorenzo/flutter_inappwebview_android/Util.java b/flutter_inappwebview_android/android/src/main/java/com/pichillilorenzo/flutter_inappwebview_android/Util.java
index a5378b7c84..1531562129 100755
--- a/flutter_inappwebview_android/android/src/main/java/com/pichillilorenzo/flutter_inappwebview_android/Util.java
+++ b/flutter_inappwebview_android/android/src/main/java/com/pichillilorenzo/flutter_inappwebview_android/Util.java
@@ -66,7 +66,7 @@ public class Util {
   private Util() {}
 
   public static String getUrlAsset(InAppWebViewFlutterPlugin plugin, String assetFilePath) throws IOException {
-    String key = (plugin.registrar != null) ? plugin.registrar.lookupKeyForAsset(assetFilePath) : plugin.flutterAssets.getAssetFilePathByName(assetFilePath);
+    String key = plugin.flutterAssets.getAssetFilePathByName(assetFilePath);
     InputStream is = null;
     IOException e = null;
 
@@ -91,7 +91,7 @@ public static String getUrlAsset(InAppWebViewFlutterPlugin plugin, String assetF
   }
 
   public static InputStream getFileAsset(InAppWebViewFlutterPlugin plugin, String assetFilePath) throws IOException {
-    String key = (plugin.registrar != null) ? plugin.registrar.lookupKeyForAsset(assetFilePath) : plugin.flutterAssets.getAssetFilePathByName(assetFilePath);
+    String key = plugin.flutterAssets.getAssetFilePathByName(assetFilePath);
     AssetManager mg = plugin.applicationContext.getResources().getAssets();
     return mg.open(key);
   }
diff --git a/flutter_inappwebview_android/android/src/main/java/com/pichillilorenzo/flutter_inappwebview_android/webview/in_app_webview/FlutterWebView.java b/flutter_inappwebview_android/android/src/main/java/com/pichillilorenzo/flutter_inappwebview_android/webview/in_app_webview/FlutterWebView.java
index 5605b68e3b..97a228bb29 100755
--- a/flutter_inappwebview_android/android/src/main/java/com/pichillilorenzo/flutter_inappwebview_android/webview/in_app_webview/FlutterWebView.java
+++ b/flutter_inappwebview_android/android/src/main/java/com/pichillilorenzo/flutter_inappwebview_android/webview/in_app_webview/FlutterWebView.java
@@ -64,7 +64,8 @@ public FlutterWebView(final InAppWebViewFlutterPlugin plugin, final Context cont
     }
 
     webView = new InAppWebView(context, plugin, id, windowId, customSettings, contextMenu, 
-            customSettings.useHybridComposition ? null : plugin.flutterView, userScripts);
+           customSettings.useHybridComposition ? null : plugin.binding.getFlutterEngine().getRenderer().getView(), userScripts);
+
     displayListenerProxy.onPostWebViewInitialization(displayManager);
 
     // set MATCH_PARENT layout params to the WebView, otherwise it won't take all the available space!
@@ -186,4 +187,4 @@ public void onFlutterViewDetached() {
       webView.setContainerView(null);
     }
   }
-}
\ No newline at end of file
+}
diff --git a/flutter_inappwebview_android/android/src/main/java/com/pichillilorenzo/flutter_inappwebview_android/webview/in_app_webview/InAppWebViewChromeClient.java b/flutter_inappwebview_android/android/src/main/java/com/pichillilorenzo/flutter_inappwebview_android/webview/in_app_webview/InAppWebViewChromeClient.java
index de544f9729..5732b21d1e 100755
--- a/flutter_inappwebview_android/android/src/main/java/com/pichillilorenzo/flutter_inappwebview_android/webview/in_app_webview/InAppWebViewChromeClient.java
+++ b/flutter_inappwebview_android/android/src/main/java/com/pichillilorenzo/flutter_inappwebview_android/webview/in_app_webview/InAppWebViewChromeClient.java
@@ -126,9 +126,7 @@ public InAppWebViewChromeClient(@NonNull final InAppWebViewFlutterPlugin plugin,
       this.inAppBrowserDelegate.getActivityResultListeners().add(this);
     }
 
-    if (plugin.registrar != null)
-      plugin.registrar.addActivityResultListener(this);
-    else if (plugin.activityPluginBinding != null)
+    if (plugin.activityPluginBinding != null)
       plugin.activityPluginBinding.addActivityResultListener(this);
   }