I have an another question, for example, I've tried to use the SP500 data from Yahoo to trade on SPX500 in FXCM. It's worked in backtest but when I try to use the script in live : it says :
no asset data for ^GSPC

the script is :

function run()
{
StartDate = 20100101;
EndDate = 20171231;
BarPeriod = 60*24; // 2 hour
LookBack = 600;

set(PRELOAD|LOGFILE|PLOTNOW);
assetHistory("^GSPC",FROM_AV);
asset("^GSPC");
PlotHeight1 = 800; // height of the chart with results
PlotWidth = 2000;

/////////////////////////////////
vars Price = series(priceClose());
vars high=series(priceHigh());
vars low=series(priceLow());
vars zerolag=series(KAMA(Price,10));
vars fastema = series(EMA(Price,50));
vars slowema = series(EMA(Price,80));

asset("SPX500");
if(fastema[0]>slowema[0])
{
enterLong();

}

if(fastema[0]<slowema[0])
{
exitLong();

}


}




there is a solution to solve the problem, to use R but this solution takes more time, more memory so it's no efficient solution.
May be you have a suggestion.
Thanks