There is no convenient way to display the value of a variable in pinescript. This is most convenient way I found.
It will follow the current bar (the position is calculated with highest/lowest and atr value, as such it will never display over the chart)
In this script we display ATR for the example
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.