It has been answered zillion times. See the following FAQ:
FAQ: How to record/download/capture/save Macromedia/Adobe Flash .FLV video RTMP stream from embedded player

If you use Replay AV and/or WM Recorder and can't find flash stream URL, then
try the following RTMP flash stream recorders: Replay Media Catcher or FLV Recorder.

Please ask for help only after trying to record flash streams with RTMP flash stream recorders.