Navigate to your Settings then Booking fields, then scroll down to the Booking details section:
If you'd like to add these to all of your entries, select Edit and then select Add to all entries before selecting Update field:
You can also add attachments to these fields, which is perfect for privacy policies.
If you head over to your Bookings tab, you can download attendances (by selecting Options). You'll be able to see which customers have consented to which field. This data can also be viewed on the Customer list.