It does not mark the black line and the graphic that's just to help understand how it works
in the above image can see the indicator works on 30 minutes chart
in the above image can see the indicator works on 5 minutes chart
therefore, it can be configured to go through several temporalities.
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.