How to build a XMLRPC client in Kotlin managing dependency with Gradle?

Question

Hi I'm working with Spring and Kotlin building an XMLRPC client but I don't find any resource about it... And I'm trying to install the apache Library to consume my xmlrpc client. This is my gradle file:

buildscript {
    ext {
        kotlinVersion = '1.2.51'
        springBootVersion = '2.0.5.RELEASE'
    }
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
        classpath("org.jetbrains.kotlin:kotlin-gradle-plugin:${kotlinVersion}")
        classpath("org.jetbrains.kotlin:kotlin-allopen:${kotlinVersion}")
        classpath("org.jetbrains.kotlin:kotlin-noarg:${kotlinVersion}")
        // docker dependency
        classpath("org.springframework.boot:spring-boot-gradle-plugin:2.0.3.RELEASE") 
        // APACHE XMLRPC DEPENDENCY
        classpath("org.apache.xmlrpc:3.1.3")
        classpath('se.transmode.gradle:gradle-docker:1.2')
    } }

The build failed because it can't find the dependency.
Does anyone have any idea how to install this dependency with Gradle Or another way how to face the XMLRPC with Kotlin and Gradle?