I am not sure if it makes a difference on being 5th or 6th though.
Group stage Champions League: place 1-4
Group stage Europa League: place 5 and DFB Cup winner
Conference League Playoffs: place 6
If the DFB Cup winner gets place 1-5, then place 7 moves up and everything goes up a step. So place 7 Conference League Playoffs, place 6 Group Phase Europa League.
If Frankfurt wins the Europa League, then that qualifies them for the group stage of the Champions League. So place 5 in the table would qualify for the Champions League group stage.