Where do provisioning profiles live in my iPhone XS?
The link you've included in your question doesn't in fact contain that quote.

The easiest way to manage the provisioning profiles on the iPhone is to open Xcode and select the menu item "Devices and Simulators" in the Window menu. Right-click on your iPhone XS and select "Show provisioning profiles".

You'll then be able to see the installed profiles, add new ones and delete existing profiles.

You cannot download a provisioning profile from the device, nor can you "beam" an installed provisioning profile. However, you can just copy the provisioning profile to the device (or store it on iCloud Drive) as an ordinary file (i.e. without actually installing it) - that file can then easily be transferred using AirDrop, email or whatever.

On the actual device you will in some instances also have a menu in Settings - General - Device Management that will list the installed profiles.