Combined indicator on tradingview.com

I'm trading 3commas bots. I need to set them up using a custom signal from the trading view. It only accepts one signal ( not a few conditions that all have to agree).So I need an indicator which would combine signals from other indicators and give me a dot or arrow on the chart, whenever all of the set up conditions from other indicators are met, so I could set up an alert message which would trigger the bot to go long, short or close the trade. Ideal scenario: I'm selecting a few indicators on my chart. Then my indicator allows me to select alert triggers ( as if I would set up alerts for this indicator) from each one of them. There should be a time how long it's valid for (by selecting how many candles. For example, it will be valid for 10 candles (adjustable)). Then it gives me a symbol on a chart, which I could select then as a trigger when setting up an alert on tradingview. How it should work: say I've 2 indicators on my chart. 21 ema and RSI. I'm selecting when RSI crosses its MA to be a first trigger. 2nd condition RSI has to be above 50. 3th condition candle has to close above 21 EMA. That's why I need the option to be able to select for how long it will be valid for. When all conditions are met it gives me a dot ( whatever) to go long. So I could select each one of them as a separate alert, but bot accepts  only one alert. I need combined conditions to give one alert. Let me know, if more details are needed. Tks