InfluxDB 2.0 sum multiple fields

from(bucket: "kraken")
  |> range(start: v.timeRangeStart, stop: v.timeRangeStop)
  |> filter(fn: (r) => r["_measurement"] == "kraken")
  |> pivot(rowKey:["_time"], columnKey: ["_field"], valueColumn: "_value")
  |> map(fn: (r) => ({ _time: r["_time"], _value: r["ADA"] + r["BTC"] + r["DOT"] + r["ETH"] + r["KSM"] + r["LINK"] + r["UNI"] + r["USD"] }))
  |> aggregateWindow(every: v.windowPeriod, fn: mean, createEmpty: false)
  |> yield(name: "mean")