How do I close a request?

Open the request on Requests. Press Close the request, pick why (Not going ahead or Duplicate) and press Close it.
To merge, open the request to keep and press Merge, then pick the other one. The other closes as a duplicate pointing at this one.
A closed request stays under Closed. Open it and press Reopen it to put it back in New.

Worth knowing

Merging loses nothing: the duplicate keeps its own words and files.