The main screen is being streamed for free into a VRChat world (and a VR headset isn’t strictly required to use VRChat):

http://vrch.at/hololive-meet (non-shortlink version)

The main stage stuff “needs reservations” but that might just be for the in-person stuff, idk. Probably best to check the VRChat and HoloEN socials or your local sapling if you need more deets.