WorldCat Navigator integrates with Voyager and creates items as they are received. It does this by making a Create Bib Request to the SIP server, which creates not only a bib, but also a MFHD and an item record. The item type and location associated with these newly created records is determined by the location used to sign in to the SIP server. I hope to explain how that item type and location is determined.
First and foremost, you must know which circulation policy the given sign up location is assigned to. You can look it up under System >> Locations as the Current Circulation Policy Group. Then, go to Circulation >> Policy Definitions and select that policy. Choose the Locations tab, find your sign in location from the selected locations on the right and click Settings. There will be a drop-down menu labelled Default Item Type. This is what will be used to determine the item type for items created via SIP. You can see we've named our item type WorldCat Local Navigator.
You can also set the Default Location which will determine the item's Permanent Location. How you set this would depend on your library's workflow.