Waterfall chart with sum bar

I would like to configure a waterfall chart that an additional bar displays the sum of the previous bars as shown here: Waterfall - JSFiddle - Code Playground

My dummy data is not hardcoded like in the sample code but depends on a SQL query based on two filters:

How can I configure my series that the chart shows a sum bar like in the example? Can I configure the series with isSum : true in JSON somehow?

The expected result should look like this but with the total bar starting from 0: