i can not find "Binaural Tones in Generate menu
There isn’t one. Generate your tone and then Duplicate it with Control-D. Make it stereo with the drop-down menu on the left of the top track > Make Stereo Track. We both know it’s not “stereo,” but it will play as Left and Right in stereo players.
Koz
There is a plug-in available here: http://wiki.audacityteam.org/wiki/Nyquist_Generate_Plug-ins#Binaural_Tones_with_Surf_2
Instructions to download and install: http://wiki.audacityteam.org/wiki/Download_Nyquist_Plug-ins#download