From the floating toolbar, click on Settings, then on the Social Media tab

Check the "Show me a copy of my site on Facebook" box and click OK, then publish.

Next, login to facebook and go to the Parallels Web Presence Builder Facebook app page. Click "Add to my page" on the left hand menu. Choose the page you wish to add this to and select.

To view your website on Facebook, go to the Facebook page you just added this application to and select Website from the menu on the left side. When revisions are made to your website they will automatically be updated on your Facebook page.