In case anyone was having the same issue was having. I updated my Sonos app and Sonos speakers to the latest versions as of May 24, 2024 and the Alarms were still not showing in the Manage section of the app. I tried force quitting the app multiple times, deleting the app and re-installing the app, etc.
What solved the problem was on the iPhone was to reset the network settings of the phone.
- In iOS go to Settings-->General-->Transfer or Reset iPhone.
- After selecting Transfer or Reset iPhone select Reset.
- After selecting Reset various options appear. Select “Reset Network Settings.”
- After the phone reboots sign back onto your wifi network.
- Open the Sonos app and the Alarms became visible.
Hope this helps someone else in the same situation.