Every day you might have a lot of new events added to your calendars, other events rescheduled or events cancelled all together. With all this shifting around, it can be a bit of a pain to navigate back to your calendar and accept or decline any invites. But you can remove this step, and RSVP directly in Fellow.
Typically, events will show up as grey in Fellow if they have not been accepted yet. If you see one of these in the wild, click on the three dots in the bottom corner of the calendar event. Then select "Yes", "No", or "Maybe". Now you're all set!
You can also change your RSVP by clicking on the same three dots and selecting a different "Going?" response.