When you first connect your Airbnb account to Guesty For Hosts, Airbnb's Instant Book booking setting is automatically turned on. The setting can be changed, but how you do it depends on which sync setting you selected at the time of listing import.
Sync Everything: Disable Instant Book in Guesty For Hosts under the listing's Booking Settings.
Sync Pricing & Availability: Turn off Instant Book in the Airbnb dashboard.
To use guest requirements, Instant Book must be turned on. If Instant book is turned off, the guest requirements are not applicable.