availabilityZoneMappings

Required. The Availability Zones where you want to create firewall endpoints for a transit gateway-attached firewall. You must specify at least one Availability Zone. Consider enabling the firewall in every Availability Zone where you have workloads to maintain Availability Zone independence.

You can modify Availability Zones later using AssociateAvailabilityZones or DisassociateAvailabilityZones, but this may briefly disrupt traffic. The AvailabilityZoneChangeProtection setting controls whether you can make these modifications.