ESC Menu Message showing? (How do you do it?!)

I know this is my 3rd post and I am deeply sorry but I was wondering how does one make a message show up when players go to the ESC window what file do I go to add a message to it?

Like in this picture on how this server did the ESC message!

Really appreciate the help! xoxo

 

greeting = 'text here' # Displayed to players when they join. Leave empty to disable. %user% = User who joined, %server% = Name of server.

server settings