Hello Sahar,

I am happy to announce that the WindowSettings now supports htmlAttributes property which sets the HTML attributes of the Window wrapper element. It can be used to set the direction of the Window like:

 const window: WindowRef = this.windowService.open({
      title: "My Window",
      content: "My Content!",
       ...
      htmlAttributes: {
        dir: "rtl",
      },
    });
  }

Please check this article for more details regarding this topic:

https://www.telerik.com/kendo-angular-ui-develop/components/dialogs/window/service/#toc-custom-html-attributes

Regards,
Martin
Progress Telerik