Navigate to Settings > Domains.
Click the XML sitemap link next to the domain you wish to update.
In the popup window, you can expand the view using the + and - to see the different pages within a particular domain.
Click Proceed.
On the next page, you can create a custom path, edit an existing one, or add a new one.
Once you’re satisfied with your updates/additions/changes, click “Generate and Save”.
A new popup window will appear. Click into the link which will direct you to a page where you can view the code of your new SiteMap.
Here you can verify the information you just entered.