They mention it, but they do not provide details:
About macOS, iOS, and iTunes server host connections and iTunes background processes
Some Apple software, including macOS, iOS, and iTunes, uses different ports and servers to connect to various services. iTunes for Windows also installs some processes that run in the background when the software is open.
Make sure that your security software is set up correctly. Setup steps vary by software, so contact the developer for specifics.
On Mac, applications signed by Apple automatically receive incoming connections. This article doesn't apply if you're using the macOS built-in Application Firewall.
The following servers are used by macOS, iOS, and iTunes:
albert.apple.com, appldnld.apple.com, configuration.apple.com, .cdn-apple.com, deimos3.apple.com, gg.apple.com, gs.apple.com, itunes.apple.com, *.itunes.apple.com, mesu.apple.com, *.mzstatic.com, skl.apple.com, swscan.apple.com, xp.apple.com
evintl-ocsp.verisign.com, evsecure-ocsp.verisign.com, *.amazonaws.com, *.digicert.com, *.symcb.com, *.symcd.com