Message board application

Hi there,
We would like to add a message board feature to our nextcloud for our users. Is that possible? I’m new to nextcloud and have no experience in creating software. Is there an app already out there that we could use? I couldn’t find one in the list, but maybe a different name is used. Or is there a different type of app that could be used for the same thing?
A point in the right direction would be much appreciated,

You could simply use an other Source for LogIn-Informations, same for an external Board. Every in an separate Subdomain an all should be fine.

Don’t think so ?