So close on a Siri shortcut (but not there)

I have Home Assistant running on my network.
I have a Shelly Plus 1 in my garage to open and close the garage
I have a reed switch attached to show the open or closed status.

In the Shelly app I see the Shelly and the reed switch correctly shows open and closed status - so it is working.

On the iPhone under Devices I see the Shelly with 1 Device.
which seems to be called Shellyplus1-abcdefghijk (the letters are the unique name).

In controls for the Shelly I see Switch_0 which toggles to open or close the garage door - so that works.

I don’t see the reed sensor anywhere.

Following directions I tried to create a shortcut
I have a Dictionary with entity_id and the shelly-abcdefg
Call switch.turn_off with data and Server set to ‘Home’ from the list

The shortcut will run, but nothing happens.

a) what is wrong with my shortcut
b) what do I need to do to see the reed switch state in the app on the iPhone
c) my Home Assistant server is accessible via a DynDNS entry (I can toggle other devices using the Home Assistant app) - will this shortcut work away from my home LAN (I don’t own a HomePod or AppleTV)?

Thanks so much for the help.