Select whether the item is optional or obligatory. Obligatory items will be automatically added to the booking and cannot be removed by the guest. An example would be an end of stay cleaning charge. Optional items can be selected by the guest with their booking. Examples might be a cooked breakfast or bike hire.
If you want to offer offer extras separate to the booking and mangage manage and/or display availability through Beds24 have a look here: [[Sell Extras like Activities or Car Rental]]