IC markets return only 200 bars when calling MarketData.GetBars

Hi, I have a problem with the function MarketData.GetBars, it return only 200. I user IC Markets broker.

How to get more bars?

Thank you so much.

using System;
using System.Diagnostics;
using System.ComponentModel;
using System.IO;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using cAlgo.API;
using cAlgo.API.Collections;
using cAlgo.API.Indicators;
using cAlgo.API.Internals;
using System.Text.Json;
using System.Text.Json.Serialization;
using System.Net.Http;
using System.Net;

namespace cAlgo.Robots
{
    [Robot(AccessRights = AccessRights.FullAccess)]
    public class Z1 : Robot
    {
        public Bars _m15Bars;
       
        protected override void OnStart()
        {
            _m15Bars = MarketData.GetBars(TimeFrame.Minute15, "AUDUSD");
            _m15Bars.LoadMoreHistory();
            Print(_m15Bars.Count);
        }

        public object getData(String symbol, DateTime barTime, bool mainData, int history_count)
        {
            Print("---");
            Print(symbol);
            Print(_m15Bars.ClosePrices.Count);
            Print("---");
            return _m15Bars.ClosePrices.Count;
        }

        protected override void OnTick()
        {
            var barTime = Bars.OpenTimes.LastValue;
            if ((barTime.Minute % 15 == 0)){
                var history_count = 199;
                Print(getData("AUDUSD", barTime, true, history_count));
            } 
        }
    }
}

LOG: