Timeseries with MongoDB data after Summation

Hey there, have sensor data across multiple days. Now I want to have the summed up sensor data points per day and visualised per day. Withe the following code I don’t get any timepoints thus no time series Visualisation.

MSYPicoSensorData.ACS7125A.aggregate([
  { "$match": { "year": { "$gt": 2022 } } },
  {
    "$group": {
      "_id": { "year": "$time.year", "month": "$time.month", "day": "$time.day" },
      "Energie": { "$sum": "$Chargingpower" }
    }
  },
  {
    "$project": {
      "_id": 0,
      "Energie": 1,
      "time": { "$dateFromParts": { "year": "$group._id.year", "month": "$group._id.month", "day": "$group._id.day" } }
    }
  },
  { "$sort": { "time": 1 } }
])