How to create team chats

I am currently trying to create team chats for different teams, but the /team command does not exist in 1.12.2 which, is the version i am trying to do this in.

I want there to be a radio option, have people on another team not be able to see that team’s chat, and a lot more configurable stuff. Again this is all in Minecraft 1.12.2 java edition.