On the Bookings page you will find all of your bookings on the calendar schedule. When you select a booking, you are taken to an Edit Booking section. 

In the Guest Access Guide Status section it will state whether or not your guest has confirmed that they have received instructions. 

Note: Once the guest has read and confirmed their understanding of instructions, the status will appear in Green. If the guest has not yet read and confirmed understanding of instructions, the access guide status will appear in Yellow and you can resend the email with the click of a button.