Open FonlineServer.cfg in Server folder and add passwords in the lines starting with Access_client, Access_tester, Access_moder and Access_admin (it's near the end of the file). For example:
Access_client = c
Access_tester = t
Access_moder = m
Access_admin = a
Of course on a public server passwords should be much longer. Now if you type for example ~getaccess admin a you will get the highest possible access to server commands from client. But there is only a few core commands, so don't be disappointed. The rest you would have to add yourself (optimally among with some command module) by writing scripts.
You are a becoming a developer not by typing a command but by having skills useful in developing a game and access to the server files / game repository.
