Simple script showing candles missing an upper or downer wick. As candles tend to have a low and a high, they will most certainly form wicks. It is rare to have wickless candles on longer time frames, so it's more relevant on 1h and above.
What can you do about it?
If you see for example a Bitcoin 4h candle that hasn't form two wicks yet, there are high chances that the missing wick will be formed at one point or another, therefore you could take a trade in the direction of the missing wick. You can set alerts on wickless candles if needed.