I've done some research on your situation, and it seems that you CAN'T take the American Opportunity Credit (AOC) unless your school has a US federal identification number. This, from the instructions from the input screen in Turbo Tax:
Beginning in 2017, taxpayers are no longer allowed to claim the American Opportunity Credit (AOC) for education expenses unless the taxpayer provides the Federal ID Number (or EIN) for the school where the expenses were incurred.
Since the AOC is often the most valuable education credit, you may want to consider just removing education expenses for a school that you can't find an EIN for. In other cases, it may be best to leave these expenses.
Eligible
Educational Institutions
Depending on the credit amount that you're not getting, it may be worth a phone call or email to the university. Here is their contact number, in case you don't already have it:
https://www.brookes.ac.uk/about-brookes/contacts-maps-and-campuses/contact-us/
You may qualify for the Lifetime Learning Credit (LLC). Go back through the interview. On the page (screenshot attached), you'll see that even though there's not an EIN entered, you'll still qualify for the LLC.
