안드로이드 에뮬레이터를 찾지를 못합니다 ㅠㅠ

IOS 에뮬레이터는 잘작동이 되는데 안드로이드는 불러오질 못하네요

react-native run android 하고 실행을 하면 아래와 같이 에러가 나요

보니까 vi 를 bash 로 작성하던데 저는 지금 iterm2 와 zsh를 사용중입니다 이게 원인일까요 ? 

info Running jetifier to migrate libraries to AndroidX. You can disable it using "--no-jetifier" flag.

(node:25517) Warning: Accessing non-existent property 'padLevels' of module exports inside circular dependency

(Use `node --trace-warnings ...` to show where the warning was created)

Jetifier found 864 file(s) to forward-jetify. Using 16 workers...

info JS server already running.

/bin/sh: adb: command not found

info Launching emulator...

error Failed to launch emulator. Reason: No emulators found as an output of `emulator -list-avds`.

warn Please launch an emulator manually or connect a device. Otherwise app may fail to launch.

info Installing the app...

Starting a Gradle Daemon (subsequent builds will be faster)

FAILURE: Build failed with an exception.

* What went wrong:

A problem occurred configuring project ':app'.

> SDK location not found. Define location with an ANDROID_SDK_ROOT environment variable or by setting the sdk.dir path in your project's local properties file at '/Users/seize/Desktop/react-native/myRn/android/local.properties'.

* Try:

Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 7s

error Failed to install the app. Make sure you have the Android development environment set up: https://facebook.github.io/react-native/docs/getting-started.html#android-development-environment. Run CLI with --verbose flag for more details.

Error: Command failed: ./gradlew app:installDebug -PreactNativeDevServerPort=8081

FAILURE: Build failed with an exception.

* What went wrong:

A problem occurred configuring project ':app'.

> SDK location not found. Define location with an ANDROID_SDK_ROOT environment variable or by setting the sdk.dir path in your project's local properties file at '/Users/seize/Desktop/react-native/myRn/android/local.properties'.

* Try:

Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 7s

    at checkExecSyncError (child_process.js:616:11)

    at execFileSync (child_process.js:634:15)

    at runOnAllDevices (/Users/seize/Desktop/react-native/myRn/node_modules/@react-native-community/cli-platform-android/build/commands/runAndroid/runOnAllDevices.js:94:39)

    at processTicksAndRejections (internal/process/task_queues.js:93:5)