flutter_tts demo code can not work

[Manrupt]

i copied example code but it can not works, it's even can not get a expect result of method flutterTts.getLanguages. I tried printing the snapshot values and got this: AsyncSnapshot(ConnectionState.waiting, null, null, null) It seem like snapshot always be waiting state. How can I fix it ? ps:
flutter_tts version 3.0.0 dart version ">=2.12.0 <3.0.0" device info: Android 11 (Oneplus 7 Pro) flutter doctor: [✓] Flutter (Channel master, 2.2.0-11.0.pre.126, on macOS 11.2.3 20D91 darwin-arm, locale zh-Hans-CN) • Flutter version 2.2.0-11.0.pre.126 at /Users/manrupt/app/flutter • Upstream repository https://github.com/flutter/flutter.git • Framework revision 600e489313 (4 weeks ago), 2021-04-15 01:04:03 -0400 • Engine revision dcdc42b715 • Dart version 2.14.0 (build 2.14.0-4.0.dev)

[✓] Android toolchain - develop for Android devices (Android SDK version 30.0.3) • Android SDK at /Users/manrupt/Library/Android/sdk • Platform android-30, build-tools 30.0.3 • Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6915495) • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS • Xcode at /Applications/Xcode.app/Contents/Developer • Xcode 12.5, Build version 12E262 • CocoaPods version 1.10.1

[✓] Chrome - develop for the web • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 4.1) • Android Studio at /Applications/Android Studio.app/Contents • Flutter plugin can be installed from: 🔨 https://plugins.jetbrains.com/plugin/9212-flutter • Dart plugin can be installed from: 🔨 https://plugins.jetbrains.com/plugin/6351-dart • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6915495)

[✓] IntelliJ IDEA Ultimate Edition (version 2021.1) • IntelliJ at /Applications/IntelliJ IDEA.app • Flutter plugin version 56.0.5 • Dart plugin version 211.7233

[✓] Connected device (2 available) • GM1910 (mobile) • 30fe4d2c • android-arm64 • Android 11 (API 30) • Chrome (web) • chrome • web-javascript • Google Chrome 90.0.4430.93

[dlutton]

@Manrupt is this still an issue with the latest release?