UNO faculty and students who are overseas may use online library resources, but they must connect to the library via the University of Nebraska Virtual Private Network (VPN) and Duo 2-factor authentication. Unfortunately, there have been too many instances of compromised University of Nebraska credentials being used from overseas (not only to access library resources!), and network authentication has been considerably strengthened as a consequence.
The UNO Information Technology Services Help Desk offers troubleshooting assistance. Their email is unohelpdesk@unomaha.edu, and they are happy to advise if you need help installing the VPN client or setting up 2-factor authentication.