Yeah, you have to write rcon pb add. I managed to solve the problem. I found out that AMX Mod was not in development longer, however AMX Mod X was. So I tried amxx and installed Pod-Bot there, included your AMX Pod-Bot Menu, and now it works
So I've certainly just installed podbot on a wrong way or something. If I remember right, I tried the command "rcon pb add" when I had AMX Mod (not amxx), and it didn't work.