If you already have a website published on your domain, note that editing the “www” record will replace your website with the landing page. To avoid this, please create a new CNAME record and configure it using the guide below.
1. Log in to your account at godaddy.com;
2. Click on DNS next to the domain you want to add the subdomain to;
3. Go to the bottom of the Records list and click on Add;
4. Select CNAME for type, enter what subdomain you wish to publish your page to in the Host field and make sure it points to secure.pageserve.co and don't forget to save.
Zone File Error
If there are any errors when you try to save your zone file, GoDaddy will show a message explaining the errors. You'll usually see this if you're trying to create a CNAME record for a sub-domain (host) that already has an existing A Record. More often than not, it's when you try to create a CNAME record for your "www" subdomain.
To fix this up, delete the A Record for your "www" subdomain then create a CNAME record for "www".