Downloading historical data in CTA backtesting module does not work

[chiefirr]

I am trying to run backtesting module, using GUI. But when I select default IF88.CEFEX ticker - it fails to find the data, Same is for AAPL.NYMEX.

- 09:18:34  initialization CTA backtesting engine
- 09:18:34  strategy file loaded  
- 09:18:50  ----------------------------------------  
- 09:18:50  IF88.CFFEX-1m start downloading historical data  
- 09:18:50   data download failed ， unable to get IF88.CFFEX historical data 
- 09:19:13  ----------------------------------------  
- 09:19:13  AAPL.NYMEX-1m start downloading historical data 
- 09:23:40   data download failed ， unable to get AAPL.NYMEX historical data 

I am using Alpaca paper trading brocker. What is a proper way to fetch the data for selected stock and to start backtesting?

[day0market]

Note: I didn't test it with Alpaca.

You should specify symbol in following format: {ticker}.{gatewayname}. In case of AAPL and Alpaca symbol would be AAPL.ALPACA

Also make sure you're connected to Alpaca. If not go to main window -> system -> Alpaca, add your creds and connect

[chiefirr]

Yeah, I have connected to Alpaca and did as you said AAPL.ALPACA - it results with error in a console:

-   File "/usr/lib/python3.7/threading.py", line 917, in _bootstrap_inner
-     self.run()
-   File "/usr/lib/python3.7/threading.py", line 865, in run
-     self._target(*self._args, **self._kwargs)
-   File "/home/andrii/PycharmProjects/ch-trading-platform/venv/lib/python3.7/site-packages/pyalgotrader-2.0.7-py3.7.egg/vnpy/app/cta_backtester/engine.py", line 345, in run_downloading
-     symbol, exchange = extract_vt_symbol(vt_symbol)
-   File "/home/andrii/PycharmProjects/ch-trading-platform/venv/lib/python3.7/site-packages/pyalgotrader-2.0.7-py3.7.egg/vnpy/trader/utility.py", line 22, in extract_vt_symbol
-     return symbol, Exchange(exchange_str)
-   File "/usr/lib/python3.7/enum.py", line 310, in __call__
-     return cls.__new__(cls, value)
-   File "/usr/lib/python3.7/enum.py", line 564, in __new__
-     raise exc
-   File "/usr/lib/python3.7/enum.py", line 548, in __new__
-     result = cls._missing_(value)
-   File "/usr/lib/python3.7/enum.py", line 577, in _missing_
-     raise ValueError("%r is not a valid %s" % (value, cls.__name__))
- ValueError: 'ALPACA' is not a valid Exchange