android-studio之错误 :(1, 0) 未找到 ID 为 'kotlin-android-extensions' 的插件

apply plugin: 'kotlin-android-extensions'. 

当我在 android studio 预览中添加这个扩展时，给我这个错误
“错误:(1, 0) 未找到 ID 为 'kotlin-android-extensions' 的插件。”。

我的构建等级

   apply plugin: 'com.android.application' 
 
android { 
    compileSdkVersion 26 
    buildToolsVersion "26.0.1" 
    defaultConfig { 
        applicationId "com.example.mohamed_elbaz.myapplication" 
        minSdkVersion 15 
        targetSdkVersion 26 
        versionCode 1 
        versionName "1.0" 
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner" 
    } 
    buildTypes { 
        release { 
            minifyEnabled false 
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro' 
        } 
    } 
} 
 
dependencies { 
    implementation fileTree(dir: 'libs', include: ['*.jar']) 
    implementation 'com.android.support:appcompat-v7:26.0.2' 
    implementation 'com.android.support.constraint:constraint-layout:1.0.2' 
    testImplementation 'junit:junit:4.12' 
    androidTestImplementation 'com.android.support.test:runner:1.0.1' 
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1' 
} 

请您参考如下方法:

To use the plugin, you have to add it in your root build.gradle file

buildscript { 
ext.kotlin_version = '1.1.60' 
    repositories { 
        jcenter() 
        maven { 
            url 'https://maven.google.com' 
        } 
    } 
 
    dependencies { 
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version" 
    } 
}