Flux query: Get rid of _measuremet _field

Hi.

I want to get max temperature per day. I use aggregatewindow but i cannot get rid of some columns in output table.

Query:

from(bucket: "openhab/autogen")
  |> range($range)
  |> filter(fn: (r) => r._measurement == "Vitocal_Aussentemperatur" and (r._field == "value"))
  |> aggregateWindow(every: 1d, fn: max)
  |> keep(columns: ["_time", "_value"])
  |> rename(columns: {_value: "Max"})

Result:

I only want the “Max” column. How to achieve this?

best regards