How do I enable chat?

I searched on Settings for the option to enable the chat menu on the right side of the screen, but I couldn’t find it.

CG staff killed the chat…

What do you mean? What happened?

There is no chat anymore. They decided to remove it.

EDIT : see here for details Coding Games and Programming Challenges to Code Better

You can use the ChelonianGall chat with userscript integration into CodinGame but its not very active.
(Edit: See this post: Discussions spaces update: the question of the chat - #79 by Remi)

More active on fr than en … better use CG official discord.