get only the last value from iobroker shelly power, if its none in range, fill with previous value.
from(bucket: "iobroker") |> range(start:0) |> filter(fn: (r) => r["_measurement"] == "shelly.0.SHPLG-S#1C032F#1.Relay0.Power") |> filter(fn: (r) => r["_field"] == "value") |> fill(usePrevious: true) |> last()
integration in grafana