ComboBox - Remote Data Source


I’m trying produce example from documentation, but I cannot do that (Service is not called)
I’m new in Vaadin 10.
What is wrong here?

<dom-module id="remote-combo-box">
            <iron-ajax url=";tagged=vaadin&amp;title=[[filter]
]&amp;site=stackoverflow" last-response="{{response}}" auto></iron-ajax>

            <vaadin-combo-box filtered-items="[[response.items]
]" filter="{{filter}}" item-value-path="question_id" item-label-path="title">

    <!-- Polymer boilerplate to register the reviews-list element -->
        class MyElement extends Polymer.Element {
            static get is() {
                return 'remote-combo-box'
        customElements.define(, MyElement);
public class RemoteComboBox extends PolymerTemplate<RemoteComboBox.MyElement> {
    public interface MyElement extends TemplateModel {
    public RemoteComboBox() {

Thanks for any help!

Not 100% (cause I’m not sure if the forum does something funny with the formatting), but you should probably replace those &amp; strings with just & so that the HTTP request goes to the correct location.