This help doc is outdated. There’s no more iTunes in the latest MacOS

You only need the iTunes app if you are using a Windows PC or if you are using a Mac that is running a macOS version prior to Catalina. On a Mac running Catalina or later, you use Finder instead of iTunes.

Both of the following statements in If you forgot your iPhone passcode - Apple Support are up to date.

This process requires a Mac or PC. If you're using a PC, make sure that it has Windows 10 or later, and that iTunes is installed. 

and

Locate your iPhone in the Finder or in iTunes on the computer that it’s connected to. (Learn how to find your connected iPhone.)

iTunes was split off into Finder functions & Music.app