Flutter Doctor

[✓] Flutter (Channel stable, v1.2.1, on Mac OS X 10.14.3 18D42, locale en-GB)
    • Flutter version 1.2.1 at /Users/username/development/flutter/flutter
    • Framework revision 8661d8aecd (4 weeks ago), 2019-02-14 19:19:53 -0800
    • Engine revision 3757390fa4
    • Dart version 2.1.2 (build 2.1.2-dev.0.0 0a7dcf17eb)

[!] Android toolchain - develop for Android devices (Android SDK version 28.0.3)
    • Android SDK at /Users/username/Library/Android/sdk
    • Android NDK location not configured (optional; useful for native profiling
      support)
    • Platform android-28, build-tools 28.0.3
    • Java binary at:
      /Library/Java/JavaVirtualMachines/openjdk-11.0.2.jdk/Contents/Home/bin/jav
      a
    • Java version OpenJDK Runtime Environment 18.9 (build 11.0.2+9)
    ✗ Android license status unknown.

[✓] iOS toolchain - develop for iOS devices (Xcode 10.1)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 10.1, Build version 10B61
    • ios-deploy 1.9.4
    • CocoaPods version 1.6.1

[!] Android Studio (not installed)
    • Android Studio not found; download from
      https://developer.android.com/studio/index.html
      (or visit https://flutter.io/setup/#android-setup for detailed
      instructions).

[✓] VS Code (version 1.32.3)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 2.24.0

[!] Connected device
    ! No devices available

! Doctor found issues in 3 categories.