the line is a calculation, where it involves reading previous candles where it determines what the current price should be.
When the REP line is above the candle, open buy and close sell, when it is below, open sell and close buy.
When setting which currency, do not forget to change the settings where they are:
1 - XBTUSD
2 - BTCUSD
3 - ETHUSD
4 - BCHBTC
may also be modified:
the Lookback bar length, stop loss settings, test date.
The best results are in the 1H time, with the default settings, but try to modify the data and if you find better results, I would be grateful if you post here.