If, when you log in to your account, you do not have direct access to the event to which you have registered, do not hesitate to consult the article "Why can't I see any event in my account? "
However it is possible that the organizer decides to give access to the event in the application without having to be registered for the event. To do this, you must use the event code communicated by the organizer (if the organizer decides to use one).