Here is manual how to easy play on BICS (like AlexBug.Com) with Raptor interface. You can see help "orbis pictus" step by step how to connect (using registered accounts, but should work for unregistered guests also) to BICS and then how to partner another player and play bughouse. Here is showed all on example You have registered 2 accounts for playing rated bughouse chess game 4 seconds for move and 2 minutes reserve (for game).
Run Raptor and then follow pictures.
And now You playing game on both boards (simulbughouse).
On next pictures is case when You play only 1 board and on second playing another player, here Tester. You can connect also 2x, as Raptor You play and as RaptorSimul You follow (= observing) second board.