You can change the URL or domain associated with your site in the editor.
Note: If you haven't published your site, see Go Live, Publish, and Set Up Your Domain.
Solution
To change the URL of an already published site:
In the side panel, click Settings, and then click Site Domain.
Click Change Site URL.
Select your new domain.
For more information on the options for setting up your domain, see Going Live: Publishing and Setting Up Your Domain.