High and low look back length can be altered, fibs and fib extensions can be shown or hidden and the background can be filled or transparent.
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.