hello!
you definitely need to have a discord because all information about the event is being disseminated in the discord server and it’s required of all participants to join the server.
other sns is not required per se, but you should have a place to post your work so that your giftee can view it! in past events, i have had people simply submit their work to the event blog and it was posted for viewing in that way, so that’s an option for you if you don’t want to post it elsewhere or have nowhere else to post it. submissions will be open on this blog for that exact reason during posting day.