If you haven't assigned a custom domain or Tilda subdomain while publishing your website, the page will have a URL like this: http://project243352.tilda.ws/page931264.html. It will work, and you can share it on Facebook. It does not look especially attractive, however.
You can choose a free custom website address on a Tilda subdomain in the Site Settings, e.g., http://mylovelysite.tilda.ws.