Call for papers & review
Camera-ready / final versions
Collect final versions from accepted authors and (optionally) mint DOIs.
After decisions, the Final versions area (sidebar) runs the camera-ready phase: accepted authors upload the final, publication-ready version of their paper.
Opening the phase
Under Final versions, turn the camera-ready phase on and set an optional deadline. Authors of accepted submissions can then upload their final file from their My submissions page — but only while the phase is open and before the deadline. A new upload replaces the previous final version.

The page lists every accepted paper with its camera-ready status, so you can see who has and hasn't submitted.
DOIs for proceedings
If your platform has DataCite configured, you can mint a DOI for each final paper from the same page — handy for published proceedings. (This depends on DataCite being set up; it's not tied to a plan.)
The camera-ready phase and deadline are event settings; the uploaded file is stored against the submission, timestamped when it lands. Reverting the phase closed stops further uploads.