Both UPS and FedEx changed their rules over the past couple of years and require the shipping label to be on an account with an FFL on file.
I’ve used shipmygun.com and had an FFL send me a prepaid label for UPS, but unless you have an account with an FFL attached they say they won’t ship otherwise.
So, for shipping a handgun you pretty much need an FFL involved. How else would you suggest shipping a handgun? I agree it’s not against the law to ship via UPS or FedEx but it’s against their policy, so if something happens during shipping you’re SOL for filing a claim.
UPS even went full retard and you can’t even ship any accessories like a mag or grip. They only allow scopes from “normal” people