Google Webmaster Tools Website Property
Before you can submit a SITE MAP using Google Webmaster Tools you must first add the website address as a WEBSITE PROPERTY.
You should then verify that you own the WEBSITE PROPERTY.
And choose one as your PREFERRED DOMAIN for use by Webmaster Tools to monitor website traffic.
When you add an SSL certificate to your website (recommended) you should add two more WEBSITE PROPERTIES to the list.
Choose one of the HTTPS properties as your new PREFERRED DOMAIN.
And verify that you own the website.