I used permission in manifiest but didn't work

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.VIBRATE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

I also used flutter build apk --release --no-shrink not worked, I also used flutter clean not wokred, I changed gradle 4.1.0 to 3.5.0 not worked, I changed distrubution graldle 6.7all to 6.5.1all not worked

Packages I used

  shared_preferences: ^2.0.6

and I used

import 'package:flutter_riverpod/flutter_riverpod.dart';

import 'pages/signup_page.dart';

void main() {
  runApp(ProviderScope(child: MyApp()));

class MyApp extends StatelessWidget {
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        primarySwatch: Colors.blue,
      home: Container(),

Solution 1: user8819119

I add multiDexEnabled, shrinkResources and minifyEnabled and solved

android {
    compileSdkVersion 30

    sourceSets {
        main.java.srcDirs += 'src/main/kotlin'

    defaultConfig {
        // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
        applicationId "com.example.assignmenet"
        minSdkVersion 16
        targetSdkVersion 30
        versionCode flutterVersionCode.toInteger()
        versionName flutterVersionName
        ndkVersion "22.1.7171670"
        multiDexEnabled true

    buildTypes {
        release {
            // TODO: Add your own signing config for the release build.
            // Signing with the debug keys for now, so `flutter run --release` works.
            signingConfig signingConfigs.debug
            shrinkResources false
            minifyEnabled false