fix

config.xml

@@ -107,4 +107,7 @@
     <plugin name="cordova-plugin-camera" spec="~4.0.3" />
     <engine name="android" spec="8.1.0" />
     <engine name="ios" spec="5.0.1" />
+    <plugin name="cordova-plugin-advanced-http" spec="2.3.1">
+        <variable name="OKHTTP_VERSION" value="3.10.0" />
+    </plugin>
 </widget>

package.json

@@ -22,14 +22,17 @@
     "@angular/router": "~8.2.11",
     "@ionic-native/camera": "^5.15.1",
     "@ionic-native/core": "^5.15.1",
+    "@ionic-native/http": "^5.19.1",
     "@ionic-native/splash-screen": "^5.15.1",
     "@ionic-native/status-bar": "^5.15.1",
     "@ionic/angular": "^4.11.1",
     "@ionic/storage": "^2.2.0",
     "cordova-android": "8.1.0",
     "cordova-ios": "5.0.1",
+    "cordova-plugin-advanced-http": "2.3.1",
     "cordova-plugin-camera": "^4.1.0",
     "cordova-plugin-device": "^2.0.3",
+    "cordova-plugin-file": "6.0.2",
     "cordova-plugin-ionic-keyboard": "^2.2.0",
     "cordova-plugin-ionic-webview": "^4.1.3",
     "cordova-plugin-splashscreen": "^5.0.3",
@@ -42,7 +45,7 @@
   },
   "devDependencies": {
     "@angular-devkit/architect": "~0.803.12",
-    "@angular-devkit/build-angular": "^0.803.12",
+    "@angular-devkit/build-angular": "^0.803.22",
     "@angular-devkit/core": "~8.3.12",
     "@angular-devkit/schematics": "~8.3.12",
     "@angular/cli": "~8.3.12",
@@ -78,7 +81,10 @@
         "ANDROID_SUPPORT_ANNOTATIONS_VERSION": "27.+"
       },
       "cordova-plugin-ionic-keyboard": {},
-      "cordova-sqlite-storage": {}
+      "cordova-sqlite-storage": {},
+      "cordova-plugin-advanced-http": {
+        "OKHTTP_VERSION": "3.10.0"
+      }
     },
     "platforms": [
       "android",

src/app/tab1/tab1.page.ts

@@ -9,7 +9,7 @@ import { UserService } from '../services/api/user.service';
 })
 export class Tab1Page {
 
-@ViewChild('jubapage') jubapage:any;
+@ViewChild('jubapage') jubapage;
 
 constructor (public UserS :UserService){