Not yet, but it is coming.
Long answer: Yes, in a pretty hacky way. You can do it in two ways:
- manually setting m.room.guest_access in all the comment section rooms you want to require authentication for
- disabling guest registration entirely for the default homeserver
But those hacks will both generate user-visible errors.
See this issue for progress on doing it "cleanly": https://gitlab.com/cactus-comments/cactus-client/-/issues/34
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