The filer requires a software license to enable HTTP service. The license is installed on the filer at the factory per your order, so the initial setup of your filer does not involve entering a license code.
You need to enter a license code only if any of the following conditions applies:
You purchased a filer with a version of Data ONTAP™ software earlier than Data ONTAP 4.0, and you just upgraded it to the current version.
You want to enable a protocol not previously licensed for your filer.
You just reinstalled the filer's file system.
Network Appliance provides you with the appropriate license codes when shipping you the software upgrade kit or when giving you instructions for obtaining the software upgrade over the Internet.