Please capitalize where necessary: if you want to travel with your pet, you can book this while making the online booking or subsequently up to 48 hours before departure via optional extras " (provided the booking was made via airberlin.com) or at our service center ".
If you want to travel with your pet, you can book this while making the online booking or subsequently up to 48 hours before departure via Optional extras " (provided the booking was made via airberlin.com) or at our Service Center ".