Android emulator not visible in flutter devices

Question

I have 2 android emulators, one being BlueStacks and the other, a Google Pixel 4 from Android Studio. When I create a new Flutter app and go to the Devices option, I couldn't see any of the android devices. Also, I tried to look for the devices using flutter devices command, but only Google and Edge appeared. Even I tried to connect BlueStacks using adb connect command, but didn't work. But it does run on Google and Edge. How to make my app android-compatible ?

C:\Windows\System32>flutter doctor
Doctor summary (to see all details, run flutter doctor -v):
[√] Flutter (Channel stable, 2.8.1, on Microsoft Windows [Version 10.0.19042.1466], locale en-IN)
[√] Android toolchain - develop for Android devices (Android SDK version 32.1.0-rc1)
[√] Chrome - develop for the web
[√] Android Studio (version 2020.3)
[√] VS Code, 64-bit edition (version 1.63.2)
[√] Connected device (2 available)

• No issues found!

C:\Windows\System32>flutter doctor -v
[√] Flutter (Channel stable, 2.8.1, on Microsoft Windows [Version 10.0.19042.1466], locale en-IN)
    • Flutter version 2.8.1 at C:\Users\User\Flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 77d935af4d (8 weeks ago), 2021-12-16 08:37:33 -0800
    • Engine revision 890a5fca2e
    • Dart version 2.15.1

[√] Android toolchain - develop for Android devices (Android SDK version 32.1.0-rc1)
    • Android SDK at C:\Program Files\Android\Sdk
    • Platform android-32, build-tools 32.1.0-rc1
    • Java binary at: C:\Program Files\Android\Android Studio\jre\bin\java
    • Java version OpenJDK Runtime Environment (build 11.0.10+0-b96-7249189)
    • All Android licenses accepted.

[√] Chrome - develop for the web
    • Chrome at C:\Program Files\Google\Chrome\Application\chrome.exe

[√] Android Studio (version 2020.3)
    • Android Studio at C:\Program Files\Android\Android Studio
    • 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 11.0.10+0-b96-7249189)

[√] VS Code, 64-bit edition (version 1.63.2)
    • VS Code at C:\Program Files\Microsoft VS Code
    • Flutter extension version 3.34.0

[√] Connected device (2 available)
    • Chrome (web) • chrome • web-javascript • Google Chrome 98.0.4758.82
    • Edge (web)   • edge   • web-javascript • Microsoft Edge 98.0.1108.43

• No issues found!

And also, can anyone explain me what is flutter channel and when and how to use it ?