@James613, I have heard anecdotally that some people cannot turn off Instant Booking. But if you can, here's where the setting is:
Go to your Hosting Dashboard and click on the "Listings" tab.
In the "Listings" tab, find the Listing you want and click on the "Manage Listing" button.
Once it has opened your listing for editing, click on the "Booking setting" tab.
In "Booking settings", the first item is the Instant Book setting. It is actually titled "How guests can book".
The option labelled "Guests who meet all your requirements can book without requesting approval" is Instant Book on.
The option labelled "All guests must send reservation requests" is turning Instant Book off.