Yes! You can check how many registrants you have for a booking, by logging into your Thriver account and clicking into the calendar icon at the top of the page, then choosing the 'Upcoming' tab. From there, click on the arrow to display the full details of your booking.
It will show a right panel with the information of the participants (including the number of invitees, registrants, and post-event attendees).
If you click on the 'Manage participants' button, it will pop up the list of all participants. You can filter by 'All registered' to view the list of the invitees (first name/last name) that have successfully registered to attend the event.