With Inline Threads, you can make comments and discuss topics with collaborators directly in your code.
To create a thread, highlight some code, right-click it, and hit Start Thread. Next, start off the conversation by sending the first message.
Open a thread by clicking on the chat icon in a code file. Type in the text box and hit the Enter key to send a message.
The Thread Inbox
To open the Thread inbox, enter a multiplayer or team Repl, open the Tools section on the sidebar, and hit Threads.