Automatic chat messagesSolved
A simple plugin that sends a server message in chat from time to time (in seconds and custom).If there is already a similar plugin I'm sorry but I didn't find it. Thank you
There are a couple free ones here that will work and a couple paid ones that work.

Here is one of the free ones here on umod:
https://umod.org/plugins/advert-messages
Timed Execute can be used for this too, or Auto Messages.
You could also use Smart Chat Bot
Locked automatically