If your chart div is enclosed within a
<form>element, you can use this configuration option to automatically add the selected seat IDs to the form data. This is one of the ways you can pass the selected seats to your server, so that you can book them later on through the Seats API.
If you use this in your configuration:
then a hidden form field with the name "selectedSeats" will be added to your form, and it will contain the selected seat IDs upon form submission, like so:
<input type="text" name="firstname" value="John">
<input type="text" name="lastname" value="Snow">
<!-- this will be generated by seats.io -->
<input type="hidden" name="selectedSeats" value="E-6,E-4,E-2">
You don't have to create the hidden form field yourself, seats.io will generate it for you.