package ${package};

import org.teavm.dom.browser.Window;
import org.teavm.dom.html.HTMLDocument;
import org.teavm.dom.html.HTMLElement;
import org.teavm.jso.JS;

public class Client {
    private static Window window = (Window)JS.getGlobal();
    private static HTMLDocument document = window.getDocument();

    public static void main(String[] args) {
        HTMLElement div = document.createElement("div");
        div.appendChild(document.createTextNode("TeaVM generated element"));
        document.getBody().appendChild(div);
    }
}

package ${package};

import org.teavm.jso.dom.html.HTMLDocument;
import org.teavm.jso.dom.html.HTMLElement;

public class Client {
    public static void main(String[] args) {
        HTMLDocument document = HTMLDocument.current();
        HTMLElement div = document.createElement("div");
        div.appendChild(document.createTextNode("TeaVM generated element"));
        document.getBody().appendChild(div);
    }
}

Fix Client.java file in maven archetype