I've had to navigate this a few times in the last year, so I hope this helps.
UPS has closed most of it's Customer Service Centers around the Country. These are the ones that used to be located at a major UPS Terminal and warehouse locations where dozens if not hundreds of UPS Semi-trucks would be loaded and unloaded daily. The job has now been farmed out to local UPS centers in your neighborhood, and most of those WILL NOT ACCEPT ammo, primers, or anything hazmat or firearm related.
What UPS now requires is for you to set up an account with them, similar to a store, or commercial vendor, including your CC information. After you set up an account, you use your computer to print a shipping label, and pickup is arranged online. You must have the proper HAZMAT label on the box prior to the pickup, as the driver is not responsible for providing one to you.