Supposedly, as of August 2024, it should be possible to see a list of every player who was banned in your game via the Roblox Creator Hub, allowing you to unban them from there without needing to do anything in Roblox Studio.
However, when I tried following the instructions outlined by Roblox in the Ban API Announcement thread, I still don’t see the “Moderation” section for any of my games.
Edit #1:Recent posts on the announcement thread seem to indicate that the “Moderation” tab was silently removed sometime within the past 24 hours, so the steps below won’t work yet until it is (hopefully) readded.
Just in case it works for you, here’s the post from Roblox that details the step-by-step instructions: