Did you get the Instrument not supported: on Oanda?
Autoview by default will use the exchange and symbol provided by Tradingview. This will match the symbol for the chart you created your alert on. Unfortunately, what Tradingview uses does not always match what the exchange API requires. So here's the best way to make sure you're using the proper symbol on Oanda.
Search the symbol directly in the chart on Oanda's interface. Click your selection and to have the end search match what their API requires.
e=oandapractice s=US SPX 500 b=long q=0.01% t=market d=1
To learn more about automating your Tradingview strategy on Oanda we recommend reviewing this article next. Command examples and parameter details