Theory.
If the candle height exceeds the average volatility, a new candle will start.
It is preferable to use 1M candles. To avoid redrawing.
But you can use regular renko candlesticks. If 1M is not enough. This indicator is designed only to calculate the average candle height.
The information is displayed as a comment.
The recommended depth is over 10,000 bars. Version (chart). This makes it easier to imagine which candles and how to stretch them.
There's always some kind of problem with Renko.
Here are the current working versions with open source.
https://www.mql5.com/ru/articles/2297