Set MuseScore 4 to tabbed mode?

Hi, I just downloaded MuseScore 4 to try it out.
How can I enable the "old style" tabbed interface - the one with only ONE Menu/Button Bar and several scores showinig in tabs?
Per default it seems, MuseScore 4 can only open one Document and you have to open a seperate program instance for every document.
I prefer one taskbar button for the PROGRAM instead of one taskbar button for each SCORE.
It must be possible some way since it still shows the score as tab:
https://musescore.org/sites/musescore.org/files/2022-12/ScoreTab.jpg