try to use console button

app/UI/Vms/Buttons/ConsoleButton.php

@@ -42,7 +42,7 @@ class ConsoleButton extends ButtonDataTableModalAction implements ClientArea
 
     public function afterInitContent()
     {
-        $serviceUrl = new UrlServiceHelper();
+        $this->serviceUrl = new UrlServiceHelper();
 //        $this->htmlAttributes['@click'] = "window.open('{$serviceUrl->getNoVncConsoleUrl()}', '', 'width=900,height=700'); return false;";
     }