If you are an ILL referral group library, you will not see the Discover Items tab in your interface. The ILL referral group interface differs from the standard WorldShare ILL module. To search for items for your requests, users are encouraged to search WorldCat.org, FirstSearch, or WorldCat Discovery.
If you are not an ILL referral group library but WorldShare is still not displaying as expected, please see the below-linked documentation for further troubleshooting steps.