Is there any way to have terminal tabs or multiplexing (screen/tmux)? Seems like a big oversight that you can't do this to say run a server in the background.
I think you are looking for Terminal in your Repl
If so, Then Hit Ctrl + Shift + S
You will see a new window under your console.
If you are looking for multiplexing then, It's not available till now.
But if you are really that interested then, give them feedback in Repl.it Feedback Section.
That's it you can try
Hope this helps