Hi, @goldriver bruno! I do not have any means to determine whether the espresso machine is on or not other than viewing the history in the Shelly app (to see that my scheduled timers activated successfully) or by looking at my machine. At the moment, this isn’t really a problem to me because I just want it turned on in the mornings for when I wake up. In the original guide I referenced over on hackster.io, Pete Stothers (the original author of that guide), wrote a comment describing his plans for determining whether it was on or off by means of a “Xiaomi Zigbee Smart Switch with power monitoring capabilities”. He has some Home Assistant template switch code that might be able to help you with this over there.
robertklep’s “a good tutorial” link is the same guide from hackster.io
Good luck!
P.S. If you’re looking for a “dumber” method of keeping track of whether the machine is on or off, the Breville Barista Express goes to “sleep” after 1 hour of being on, and turns “off” after 3 hours of being on. So you may be able to code around when you expect the thing to be on or off based on when you sent the “on” command to the relay.