I'm not one hundred percent positive, but I do believe GoDaddy has the FedEx option for shipping but I don't think it's available for the Website Builder/GoCentral. I think you would need a different web hosting service package from GoDaddy to set up the FedEx option for shipping.
I think only USPS and UPS is available to use with the Website Builder/GoCentral.
If you click on the Go Central / Website Builder forum, you'll see monthly posts pinned at the top outlining any new updates and features from the GoCentral team. They are constantly adding new features in addition to enhancing other features as well!