Registrations were open in June and November 2019 last time, but it's not guaranteed when they will be open next. I'd recommend keeping on the lookout, here or on twitter through keywords, that's how I knew registrations were open last June and got in (if I'm not slammed with work and happen to not miss the info, I also try to post it here). Also, I see people requesting invites: I wouldn't count on it. As someone said before, you're responsible for the people you invite, and it's also very costly to get even one invitation. Given those factors, it's highly unlikely anyone would offer an invite, especially to people they don't know. The only real way to get in is to wait for registrations to open.