Hi gennargiu! Can you add some detail? You started with MX-21 Xfce B2, then what? Did you use MX Package Installer to add Fluxbox WM? If yes, what did you do then? Did you run MX Fluxbox using the Xfce menu or rofi (Logo key)? And then what do you mean by "it doesn't work" exactly?
hello and ...