You need to use the Hotel Confirmation Number which is usually a six digit one that includes letters and you can find it on your confirmation e-mail or on My Trips on the Orbitz page. It will be in the section where they describe which resort you booked and the dates. Do not use the Orbitz record locator reference number.
If you can't find it, then call Orbitz and ask them for the Disney reservation number.
Remember to change the shipping address for the Magic Bands to your address because it will default to the Orbitz corporate address.