account is not defined? keyring is not defined? When I'm running, gave me these tips.And I cannot create mnemonics.

[CodeSkyCode]

Launching lib/main.dart on STF AL10 in debug mode...
Running Gradle task 'assembleDebug'...
✓ Built build/app/outputs/flutter-apk/app-debug.apk.
I/flutter ( 3164): _handleInitialUri called
I/flutter ( 3164): No observables detected in the build method of Widget
I/flutter ( 3164): no initial uri
I/flutter ( 3164): _keyringEVM.keyPairs.length===0====_keyringEVM.contacts.length0
I/flutter ( 3164): Server running on http://localhost:8080
I/flutter ( 3164): HeadlessInAppWebView created!
I/flutter ( 3164): CONSOLE MESSAGE: Uncaught SyntaxError: Unexpected token .
I/flutter ( 3164): Unable to load asset: "./favicon.ico".
I/flutter ( 3164): webview loaded http://localhost:8080/packages/polkawallet_sdk/assets/index.html
I/flutter ( 3164): CONSOLE MESSAGE: Uncaught ReferenceError: account is not defined
I/flutter ( 3164): js update: polkadot 34802 34802 10011
I/flutter ( 3164): bridge js update: 36001 35702
I/flutter ( 3164): CONSOLE MESSAGE: Uncaught ReferenceError: keyring is not defined
I/flutter ( 3164): CONSOLE MESSAGE: Uncaught ReferenceError: keyring is not defined