I've just received my first Shelly device, a Dimmer 2 and have this exact setup. Struggling to get it working properly though.
Attached how it's wired, same as mentioned above. Odd thing is that I need to switch it twice to turn on, and twice to turn off again. Also the state does not seem to get fed back to either the Shelly app or the Google Home app.
Feels like lit's close, but I'm not quite there!