how do I convert trading views STDDEV(values: a -b, period: 20) to talib or technical indicators library?

I use Nodejs and react for visualization. I wonder why nodejs gets so much hate or so little attention here? I just create my own web sockets with W3websocket and pull directly from api with axios instead of using a library. Technical-indicators library works well for me as well. Although I’m having trouble figuring out how trading view does certain things like standard deviations and what amount of dev? What is optInDev in TALIB and how do I convert trading views STDDEV(values: a -b, period: 20) to talib or technical indicators library? I made my own rudimentary backtesting just subtracting money by the close price times the asset of that candles close or divide to add the other way around