Install bbpager by entering the following commands in the terminal:
sudo apt update sudo apt install bbpager
Pager for the blackbox and fluxbox window managers
A pager tool for the Blackbox window manager or one of its derivatives. It supports the usual Blackbox styles, moving windows between desktops, and optional placement in the Blackbox slit. It is also possible to define how the desktops are displayed by defining the number of rows or columns to use.