Overview

The following article describes the Android SDK requirements

compileSdkVersion 30 

android {
    ....
    compileSdkVersion 30
    }

AndroidX minSdkVersion 21 or higher

    android {
        minSdkVersion 21
        ...
}

Android Support minSdkVersion 21 or higher

    android {
        minSdkVersion 21
        ...
}

JavaVersion.VERSION_1_8

android {
    compileOptions {
        targetCompatibility JavaVersion.VERSION_1_8
     }
}

App Permissions requirements (AndroidManifest)

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>