This simple script is a modification of Tradingview's Up/Down Volume. In this case the delta between the buys and sells is plotted in columns style above the regular up/down volume columns. This gives a better visual of the dominant volume and is useful to spot divergences in tops and bottoms.
The indicators uses data from lower timeframe volumes. By default the lowest timeframe it will use is 1m, but for those that have a premium account you can try using a custom LTF set to seconds when scalping on the 1m chart.