MT4 Historical Data for Backtesting?

Backtesting a strategy on US30, M15 timeframe, in MT4. I have the code completed for the strategy and I have back-tested the strategy against the data provided in MT4. However, the history centre in MT4 only stores four weeks worth of data. On attempting to download more data in the history centre, I get a message stating that there is no additional data available for the symbol. Just wondering where I can source more test data for US30 M15? Have had a look online and I can find D1 data but not M15 data.

you can get data from here
https://www.dukascopy.com/swiss/engl...ch/historical/

Thanks. Tried this site already and it keeps hanging at 50% when you try to download data. Tried to download two years as a test. Seeing a HTTP 503 error in the dev tools.

yeh, sometime it give error but it works
or.........
you can try this, open new demo acc then get same data like TradingView
I used to get information from this broker with a demo account for practice and backtest
https://www.oanda.com/bvi-en/cfds/platforms/
https://www.oanda.com/us-en/trading/.../metatrader-4/