Some of the meeting rooms in the Orbit app requires check in. Some don't. This is because every host can decide what rules should apply for their meeting rooms.
You can see if your booking requires check-in when you book:
Why some host's require check in on their meeting rooms
Meeting rooms are booked in advance and people sometimes forget to cancel if they don't use it, or forget to check out when they are done with the meeting before scheduled end-time. This causes spaces to be left empty and unused as these spaces are unavailable in the Orbit app while remaining booked and unused. With the check-in functionality we make sure that unused space will be made available for others to use.