Cannot change your alarm sound on HomePod

I'm trying to set the alarm sound on my HomePod and found the instructions at Use alarms, clocks and timers – Apple Support (UK). However, when I go in to the HomePod via the Home app I don't see any alarm options listed. This is despite actually having an alarm set. My HomePod is on version 17.2.

Is the documentation correct?

Many thanks,

Ian