Creating jar from javaFX gradle project

New to Gradle, and trying to make a executable jar so I can run my project on a raspberry PI. It builds and runs succesfully, and after building jar with the gradle panel on the right in intellij, I try to run it with

java -jar .\build\libs\<name of jar file>

It then gets an error: 
Error: Could not find or load main class org.openjfx.MainApp
Caused by: java.lang.NoClassDefFoundError: javafx/application/Application

My build.gradle file:

plugins {
    id 'application'
    id 'org.openjfx.javafxplugin' version '0.0.8'
}

jar {
    manifest {
        attributes 'Main-Class': 'org.openjfx.MainApp'
    }
}

repositories {
    mavenCentral()
    jcenter()
}

dependencies {
    compile 'org.kordamp.ikonli:ikonli-javafx:11.3.4'
    compile 'org.kordamp.ikonli:ikonli-weathericons-pack:11.3.4'
    compile group: 'org.dom4j', name: 'dom4j', version: '2.1.0'
    compile 'joda-time:joda-time:2.10.3'
    compile 'com.google.api-client:google-api-client:1.23.0' // Google cal
    compile 'com.google.oauth-client:google-oauth-client-jetty:1.23.0' // Google cal
    compile 'com.google.apis:google-api-services-calendar:v3-rev305-1.23.0' // Google cal
}

javafx {
    version = "12.0.2"
    modules = [ 'javafx.controls', 'javafx.fxml' ]
}



mainClassName = 'org.openjfx.MainApp'
sourceCompatibility = 1.8 // Google cal
targetCompatibility = 1.8 // Google cal
version = '1.0' // Google cal

Started out with this simple guide: https://openjfx.io/openjfx-docs/
This was a simple JavaFX and IntelliJ with Gradle project, and then added some dependencies, and classes. 
Runs ok, but  when I stop I also get this fail:
Execution failed for task ':run'.
> Process 'command 'C:\Program Files\Java\jdk-12.0.2\bin\java.exe'' finished with non-zero exit value 1

Maybe it has something to do with that, but don't understand the whole gradle process yet.

Appreciate all the help I can get