In short
The featured event in Discover has one of two buttons. I’m interested is a single tap that tells the organizer you’re interested. Reply appears instead when the organizer has published an invitation for the event; it opens that invitation so you can answer it, the same way you reply to any Linxy invitation.
On this page
I’m interested
One tap; you’ll see Marked as interested. It tells the organizer you’re interested — it isn’t a ticket and doesn’t reserve a place.
Reply
When the event has a published invitation, the button reads Reply. It opens the invitation, where you answer the organizer’s questions and can connect with the event. Inside the event, the Going / Maybe / Interested buttons disappear once you’ve checked in.
For organizers
When your event has a published invitation, the featured spot shows Reply instead of I’m interested. An invitation for a public event can be opened by anyone who has its link, so it suits open events.
Related reading: Replying to an invitation and Host videos and “Presented by” on events.