Currently, all the members see the chat, no matter what project they are in.
That is confusing if you have people talking about different projects at the same time.
Is it possible to make a chat room per project?
Are you referring to " kanboard / plugin-chat"? This plugin is no longer maintained. Last update was in 2018.
Better idea to embed another chat software on the project pages. Do you already some some chat software at your organization? If you don’t ahve one, I recommend rocket.chat.
You will need to edit project pages to add an iframe or something like it.
Something like tawk.to?