The sites created through this service are bound to your web browser, with their data saved in the browser’s storage. That means you can’t access the site from another device. But you can move your site to a dedicated WordPress host if you ever want to make it public.
https://techcrunch.com/2026/03/11/wordpress-debuts-a-private-workspace-that-runs-in-your-browser-via-a-new-service-my-wordpress-net/