The AMS 2 Pro has two active air inlets and outlets, with the lower one serving as the inlet and the rear one as the outlet. The dampers in the inlet (side wall) and outlet (base) assemblies are identical and differ only in cable length.
When drying the filament, the AMS 2 Pro removes moisture from the interior via external circulation. During this external circulation, the air inlets and outlets are opened. Please ensure that these are not blocked by any debris to achieve optimal drying performance.
Further information can be found on the Bambu Lab Wiki.