flutter for web の環境構築でchromeがdeviceに追加されない

前提・実現したいこと

flutter webの環境構築。
android studioのバージョンは4.0です。
下記、flutter doctorの実行結果です。

Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel beta, 1.24.0-10.2.pre, on Mac OS X 10.15.7 19H2 darwin-x64, locale ja-JP)
[✓] Android toolchain - develop for Android devices (Android SDK version 29.0.3)
[✓] Xcode - develop for iOS and macOS (Xcode 11.5)
[✓] Android Studio (version 4.0)
[!] Connected device
    ! No devices available

! Doctor found issues in 1 category.

発生している問題・エラーメッセージ

flutter for web の環境構築でchromeがdeviceに追加されない。
下記flutter devices実行結果。

No devices detected.

Run "flutter emulators" to list and start any available device emulators.

If you expected your device to be detected, please run "flutter doctor" to diagnose potential issues. You may also try increasing the time to wait for connected devices with the --device-timeout
flag. Visit https://flutter.dev/setup/ for troubleshooting tips.