Error Android Plugin with id 'jetty' not found

My question is this.

I just created a project and it does not let me synchronize the Gradle, it puts me all the time that it does not find the jetty plugin, I tried to download the gradle version, change the classpath, ... but doing this tells me that There is a newer version and I have to update it.

What would I have to do to make it work for me?

This is the html code:

apply plugin: "java"
apply plugin: "jetty"

gwt {
    gwtVersion='2.8.0' // Should match the gwt version used for building the gwt backend
    maxHeapSize="1G" // Default 256m is not enough for gwt compiler. GWT is HUNGRY
    minHeapSize="1G"

    src = files(file("src/")) // Needs to be in front of "modules" below.
    modules 'com.mygdx.game.GdxDefinition'
    devModules 'com.mygdx.game.GdxDefinitionSuperdev'
    project.webAppDirName = 'webapp'

    compiler {
        strict = true;
        disableCastChecking = true;
    }
}

task draftRun(type: JettyRunWar) {
    dependsOn draftWar
    dependsOn.remove('war')
    webApp=draftWar.archivePath
    daemon=true
}

task superDev(type: de.richsource.gradle.plugins.gwt.GwtSuperDev) {
    dependsOn draftRun
    doFirst {
        gwt.modules = gwt.devModules
    }
}

task dist(dependsOn: [clean, compileGwt]) {
    doLast {
        file("build/dist").mkdirs()
        copy {
            from "build/gwt/out"
            into "build/dist"
        }
        copy {
            from "webapp"
            into "build/dist"
            }
        copy {
            from "war"
            into "build/dist"
        }
    }
}

draftWar {
   from "war"
}

task addSource {
    doLast {
        sourceSets.main.compileClasspath += files(project(':core').sourceSets.main.allJava.srcDirs)
    }
}

tasks.compileGwt.dependsOn(addSource)
tasks.draftCompileGwt.dependsOn(addSource)

sourceCompatibility = 1.6
sourceSets.main.java.srcDirs = [ "src/" ]


eclipse.project {
    name = appName + "-html"
}

Y este es el de test:
buildscript {


    repositories {
        mavenLocal()
        mavenCentral()
        maven { url "https://oss.sonatype.org/content/repositories/snapshots/" }
        jcenter()
    }
    dependencies {
        classpath 'de.richsource.gradle.plugins:gwt-gradle-plugin:0.6'
        classpath 'com.android.tools.build:gradle:3.0.1'
        classpath 'com.mobidevelop.robovm:robovm-gradle-plugin:2.3.1'


    }
}

allprojects {
    apply plugin: "eclipse"
    apply plugin: "idea"

    version = '1.0'
    ext {
        appName = "my-gdx-game"
        gdxVersion = '1.9.8'
        roboVMVersion = '2.3.1'
        box2DLightsVersion = '1.4'
        ashleyVersion = '1.7.0'
        aiVersion = '1.8.0'
    }

    repositories {
        mavenLocal()
        mavenCentral()
        maven { url "https://oss.sonatype.org/content/repositories/snapshots/" }
        maven { url "https://oss.sonatype.org/content/repositories/releases/" }
    }
}

project(":desktop") {
    apply plugin: "java"


    dependencies {
        compile project(":core")
        compile "com.badlogicgames.gdx:gdx-backend-lwjgl:$gdxVersion"
        compile "com.badlogicgames.gdx:gdx-platform:$gdxVersion:natives-desktop"
        compile "com.badlogicgames.gdx:gdx-box2d-platform:$gdxVersion:natives-desktop"

    }
}

project(":android") {
    apply plugin: "android"

    configurations { natives }

    dependencies {
        compile project(":core")
        compile "com.badlogicgames.gdx:gdx-backend-android:$gdxVersion"
        natives "com.badlogicgames.gdx:gdx-platform:$gdxVersion:natives-armeabi"
        natives "com.badlogicgames.gdx:gdx-platform:$gdxVersion:natives-armeabi-v7a"
        natives "com.badlogicgames.gdx:gdx-platform:$gdxVersion:natives-arm64-v8a"
        natives "com.badlogicgames.gdx:gdx-platform:$gdxVersion:natives-x86"
        natives "com.badlogicgames.gdx:gdx-platform:$gdxVersion:natives-x86_64"
        compile "com.badlogicgames.gdx:gdx-box2d:$gdxVersion"
        natives "com.badlogicgames.gdx:gdx-box2d-platform:$gdxVersion:natives-armeabi"
        natives "com.badlogicgames.gdx:gdx-box2d-platform:$gdxVersion:natives-armeabi-v7a"
        natives "com.badlogicgames.gdx:gdx-box2d-platform:$gdxVersion:natives-arm64-v8a"
        natives "com.badlogicgames.gdx:gdx-box2d-platform:$gdxVersion:natives-x86"
        natives "com.badlogicgames.gdx:gdx-box2d-platform:$gdxVersion:natives-x86_64"

    }
}

project(":ios") {
    apply plugin: "java"
    apply plugin: "robovm"


    dependencies {
        compile project(":core")
        compile "com.mobidevelop.robovm:robovm-rt:$roboVMVersion"
        compile "com.mobidevelop.robovm:robovm-cocoatouch:$roboVMVersion"
        compile "com.badlogicgames.gdx:gdx-backend-robovm:$gdxVersion"
        compile "com.badlogicgames.gdx:gdx-platform:$gdxVersion:natives-ios"
        compile "com.badlogicgames.gdx:gdx-box2d-platform:$gdxVersion:natives-ios"

    }
}

project(":html") {
    apply plugin: "gwt"
    apply plugin: "war"


    dependencies {
        compile project(":core")
        compile "com.badlogicgames.gdx:gdx-backend-gwt:$gdxVersion"
        compile "com.badlogicgames.gdx:gdx:$gdxVersion:sources"
        compile "com.badlogicgames.gdx:gdx-backend-gwt:$gdxVersion:sources"
        compile "com.badlogicgames.gdx:gdx-box2d:$gdxVersion:sources"
        compile "com.badlogicgames.gdx:gdx-box2d-gwt:$gdxVersion:sources"

    }
}

project(":core") {
    apply plugin: "java"


    dependencies {
        compile "com.badlogicgames.gdx:gdx:$gdxVersion"
        compile "com.badlogicgames.gdx:gdx-box2d:$gdxVersion"

    }
}

tasks.eclipse.doLast {
    delete ".project"
}

If you can help me, it would be very helpful, thank you very much