Tap the calendar icon at the bottom of the screen (second from right) to find the complete list of events being hosted on Hio. Tap on the magnifying glass on the bottom right of this screen to search for your specific event. Once you see it, tap in!
If the event is public, no passcode will be required, so you only need to select "Attending".
If the event is set to private, you will need a passcode to enter. This can be found in the email sent to you by the organizer if you have already registered.
If you have not registered and want to join the event, tap the "Buy ticket" option on the passcode screen. You'll be routed to register and purchase a ticket if necessary. You will then receive an email with the passcode that allows entrance into the event on Hio!