I am trying to Swap-in my pre-recording to Listen Again but it doesn't show up on the drop-down list
See this guide for instructions on Swapping-in recordings to Listen Again. This only applies to sessions where you have a pre-recording to use in stead of a live event or want to replace the Listen Again session with a different video. This does not apply to live timetabled sessions which will automatically use the Zoom recording for you.
Listen Again is only listing recordings that are stored in the user's PRID (top level in Panopto) folder. If staff have stored the pre-recording/video outside of this top-level folder within Panopto, then the recording needs to be manually moved into the PRID (top-level) folder.
Click http://www1.essex.ac.uk/it/docs/help/listen-again-swap-a-recording.pdf link to open the full guide on swapping.