For FXS you see the below (or similar in your config). You could also type them in the room if you have co-host access. Not sure what FXS version you use but that should work.
/ChatPassword Forbidden <------ change the word Forbidden to the password you want
/ChatPasswordOpt Msg=This Room Is Password Protected <------ change to the message that you would like to appear
/ChatPasswordOpt Correct=Password OK
/ChatPasswordOpt Wrong=Wrong password, disconnecting...
/ChatPasswordOpt TimedOut=Timed out, disconnecting...
/ChatPasswordOpt TimeOutMs=15000 <------ gives them 15 seconds to type the password - change it to whatever time you would like to give
WCS doesnt have the ability to password protect a room.
Hope that helps you Jennifer