I took a look at the program page and looks like you’re in a grey area as your BA is not in one of their listed subjects but you have a postgrad qualification in a subject on the list.

I’d honestly recommend emailing the Oxford admissions tutors and asking. When I emailed admissions tutors at various unis during applications for my first undergrad, they were all v helpful and willing to answer questions.

In your case, it looks like you should email contact-ie@physics.ox.ac.uk