Squarespace Domain showing

Site URL: https://www.aceofspadeswitchery.com

Hi guys, 

I have just purchased a www. domain for my new site that I am looking to publish... first time user here. When I am logged in, navigating around looking at pages, settings, marketing etc it is still showing the built in squarespace domain url in the top bar rather than my own? When I hit publish, will my new www. domain be the one that is active to the world? Does your generic built in squarespace domain always show as a rule of thumb when you are logged into the back end ? 
 

Thanks all 

Make sure in settings-domains, you have set  your new one the prime one. 

Please make your "third party" domain as a "primary domain" from your domain settings option.