Everyone has different ideas of which MA/ settings to use and they're all kinda highlighting the same areas whether it's 10/20, 12/26, 9/21, etc., but it stands to reason that these ones are well respected areas given that the majority of action is on Binance (for now) and it's particularly apparent on 4h charts.
In true TradingView spirit, the author of this script has published it open-source, so traders can understand and verify it. Cheers to the author! You may use it for free, but reuse of this code in a publication is governed by House Rules. You can favorite it to use it on a chart.