In the Gradle file, mention the Kotlin dependency and the application Gradle version. Here are the details of my Android Studio's Gradle file:

buildscript {
    ext.kotlin_version = '1.3.10'
    repositories {
        google()
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.2.1'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        google()
        jcenter()
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

Here, our Gradle version is 3.2.1 and the Kotlin version is 1.3.10