Help me please

I cant use the chat in game or in lobby. I can type in it, but when i hit enter nothing happens. I cannot find any button on the toolbars either that would send a message in the chat. I can see on here it says post topic(Alt+S)

So i may have to do something like that, however my computer is a mac, so it does not have an (Alt) key, it has a Command key but if i hit (Command+S) then it saves the page im on. Help please, Ive lost a lot of battles because i couldnt communicate with my alliance.

You can disable chat by not clicking tick and then you can write or read
list of chats :
private chat : you can send private message to player and he only read it , you can send the private message by clicking in player name or ''/pr playername message''
room chat : if you write in room chat , every player in lobby can read what you write
game chat : if you write in game chat , only players in that game can read what you say
coalition chat : if you write there , only your coalition members can ready that
alliance chat : if you write there , only your allies can read what you say , if you peace with a player , he can't read your alliance chat .
global chat : every player in the whole game whereever he was can see global chat .
and that's it

Hmm if your language not English , you have to tick 'write in English' button to write

Try Safari if you haven't already, as far as I know it's the only Mac browser where atWar works without issues.