Supertrend for Renko

I need help with this Supertrend cBot, but I do not know how doing it correctly. Any help is very appreciated.

using System;
using System.Linq;
using cAlgo.API;
using cAlgo.API.Indicators;
using cAlgo.API.Internals;
using cAlgo.Indicators;

namespace cAlgo
{
    [Robot(TimeZone = TimeZones.UTC, AccessRights = AccessRights.None)]
    public class RenkoSupertrend : Robot
    {
        [Parameter("UpTrend", DefaultValue = 2, MinValue = 0)]
        public int UpTrend { get; set; }

        [Parameter("DownTrend", DefaultValue = 3, MinValue = 0)]
        public int DownTrend { get; set; }

        [Parameter("Quantity (Lots)", DefaultValue = 1, MinValue = 0.01, Step = 0.01)]
        public double Quantity { get; set; }

        private Supertrend cTrend;

        protected override void OnStart()
        {
            cTrend = Indicators.GetIndicator<Supertrend>(UpTrend, DownTrend);
            var tradeType = cTrend.Result.LastValue < Symbol.Bid ? TradeType.Buy : TradeType.Sell;

            var volumeInUnits = Symbol.QuantityToVolume(Quantity);
            ExecuteMarketOrder(tradeType, Symbol, volumeInUnits, "Supertrend");
        }

        protected override void OnTick()
        {
            var position = Positions.Find("cTrend", Symbol);

            if (position == null)
                Stop();

            else
            {
                double newStopLoss = cTrend.Result.LastValue;
                bool isProtected = position.StopLoss.HasValue;

                if (position.TradeType == TradeType.Buy && isProtected)
                {
                    if (newStopLoss > Symbol.Bid)
                        return;
                    if (newStopLoss - position.StopLoss < Symbol.TickSize)
                        return;
                }

                if (position.TradeType == TradeType.Sell && isProtected)
                {
                    if (newStopLoss < Symbol.Bid)
                        return;
                    if (position.StopLoss - newStopLoss < Symbol.TickSize)
                        return;
                }

                ModifyPosition(position, newStopLoss, null);
            }
        }
    }
}