packages/webview_flutter/webview_flutter_android/example/android/app/src/debug/AndroidManifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="io.flutter.plugins.webviewflutterexample">
    <!-- Flutter needs it to communicate with the running application
         to allow setting breakpoints, to provide hot reload, etc.
    -->
    <uses-permission android:name="android.permission.INTERNET"/>
    <application android:usesCleartextTraffic="true">
        <activity
            android:name=".WebViewTestActivity"
            android:launchMode="singleTop"
            android:theme="@style/LaunchTheme"
            android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
            android:hardwareAccelerated="true"
            android:windowSoftInputMode="adjustResize">
        </activity>
    </application>
</manifest>