This box shows all of your available addons that you've created. Use this to
assign the available addon(s) to specific event types.
Before you can assign a addon(s), you must create one. This can be done by clicking "setup", then "pricing", then "Add-Ons".
Note: To select multiple addons, simply hold CTRL and click on each that you want to
select. Holding CTRL will allow you to select more than one additional package.