Summarize two pivot table columns

[RStadelmann]

Hello community

I have a question regarding pivot tables. I want to summarize two values and the result should be displayed in a new column within the same pivot table. I did not find a way to do this.

The table I want to create should look like this:

Column "E" is what I am still missing. I cannot get it to work.

I would appreciate if anyone had some advice for me.

Thank you.