code: def get_period_last_3_months() -> str:
      
      today = Datum()
      today.today()
  
      # start_date = today - timedelta(weeks=13)
      start_date = today.clone()
      start_date.subtract_months(3)
  
      period = get_period(start_date.date, today.date)
      return period
docs: Returns the last week as a period string