I recently wanted to check out an event's description in more detail but it only had the companion code and entered it to read more about an upcoming event. I realized it didn't let me leave the event afterwards and there is a small fee for signing up and not showing up so I managed to cancel it just in time through a phone call as the store was about to close. I think you should be able to leave an event at any time through the app and the event hadn't even started yet. The starting time was marked on the next day.

It feels a bit risky that someone can just accidentally sign up to something to look at the description and then can't leave and potentially has to pay for not showing up.