Please note: Event hosts do not have the option to RSVP to their own events, and therefore the RSVP button is not visible for them.
RSVP to an online invitation is done within the event invitation page that was shared with the guests, either by email or a direct link.
Click the green RSVP button, then choose RSVP status and confirm. In some cases guests also need to fill their names and email addresses and indicate number of additional guests.
After RSVP is submitted, it is possible to change the RSVP status by clicking the green RSVP button again.