The Advanced Forms add-on now allows you to set your “email”-type custom fields as recipients for your booking notifications.
For that, you first need to add an “email”-type field to your booking form (once, or for each participant), so the customers can fill it out with their email address.
The custom field type must be “Email”Then, select that custom field in the “Additional recipients (custom fields)” option in each desired notification settings.
Once the booking is made, these notifications for that booking will be sent to the all of the email addresses provided by the customer (that is, to all participants, or to additionnal recipients).