Acquiring a PTE Number

New transfer here; currently a linguistics major and in the process of changing to the combined linguistics and computer science major. I’m trying to enroll in a com sci class, however enrollment is restricted to certain majors and linguistics is not one of them. At my orientation I was told that I would only be restricted for the first pass, but as my second enrollment pass has come around, it seems that I still cannot enroll. my.ucla gives me an option to enter a PTE #, which confuses me a bit as I thought that PTE #s were only for students on the wait list? Would acquiring a PTE # allow me to enroll in the course? Would it override the major restriction? If so, do I receive one from the instructor on the first day? That’s how it worked at the college that I came from… you show up on the first day and ask the instructor if you can get a code. I’m assuming this is the same for UCLA, or should I shoot an email to someone? If anyone wants to give advice on enrolling in restricted classes/getting PTE #s I would be very grateful.