RSI can work better to know the overbought and oversold, though of course to have a clearer view it is still advisable to use other indicators.
BB and RSI are trading tools that detect not only the overbought and oversold conditions of the market but also the trend, which makes them powerful. Nonetheless, they still need other indicators and strategies for better confirmation to increase their percentage of winning.
I have been using BB and RSI for quite sometimes now, it works effectively, but with little failure which most often got corrected if the market is not that volatile, I prefer to use 1x leverage. If the market is not favoured, I changed the leverage from 1x to 3x (the max that I can go), just to take closers the mark price I will start making profit. If the market is not very volatile, the market would correct itself and I can make some profit from the position opened. The problem I had in the past is the extreme volatile market, that go against the position opened, even taking it from 1x to 3x without no market correction makes the losses to be more. Because of this, I have prefer to just trade more in market that is not that volatile, just as bitcoin as been within $21000 and $25000 range for over a month or two months now.
Some good traders have always said that only two indicators are not enough, also people said using too many indicators can make trading analysis to become another thing that may not be helpful. Although, I prefer these two indicators, I know some pros and cons of the indicators and I prefer using it just during less volatile market. But if I want to make use of other indicators, which ones are recommendable? I am not talking about the unnecessary ones that would only complicate the ones I prefer already.
As for the bot question, I also read the post of other users, paying for the bot is not wise to me. I only know of the MT4 trading platform capable of sending such signal/confirmation to Emails and texts through EA for free. If you need an exchange with such a feature for free, it is good to inquire directly from the trusted ones you know.
I will try MT4, but it is for forex I guess, or not for only forex? Is it having BTC/USDT or BTC/USD margin or derivative trading pair? Although, I am not planning to use it for crypto trading, I have preferred to use Binance and OKX but they are not having the features I asked above, but it can be a useful too just for notifications.