When you create a Booking Engine API instance, you decide if potential guests will be able to book a reservation and pay for it immediately or only send you a request to book a reservation, known as an "inquiry". Inquiries need to be confirmed manually. Follow the instructions below.
Step by step:
Sign in to your Guesty account.
From the top menu, click Reservations.
Click the relevant reservation.
To the right of "Summary", click the pencil icon.
From the drop-down under "Status", select Confirmed.
To the right of "Summary", click Save.
The dates of the confirmed reservation will be blocked on all connected booking channels.