Created attachment 113843 [details] function XXX The function bar consumes space. Why are you stuck there? Are you using DOS now? There is no option in the settings to remove it.
https://docs.kde.org/trunk5/en/extragear-utils/krusader/settings-menu.html and https://docs.kde.org/trunk5/en/extragear-utils/krusader/konfigurator.html
As Burkhard pointet out, this is easily possible.
This interface is the residue of DOS. Developers should throw away as soon as possible. It is too inconvenient to use. In the option, Interface like Ubuntu File Manager, Nemo Replace, Hotkey also provides replacements like File Manager and Nemo Please provide options. Many people should use it.