Note :: because Pinescript does not allow changes to already drawn charts on historical bars, checkbox "show only last box" doesn't work for arrows
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.