How do you use commands?

[WezKal]

I'm new here and loving all of these mods, but I can't figure out how to use the commands that I've seen listed on some of them. Is there a command prompt I need to do or something in a menu I'm missing? Thanks for any help with my noob issue

 

[Pac_Fan_456]

You just have to write them in the chat with the "/" sign.

ex: /example