It is a typical pre screen for the program via get accepted. You either pass or don’t, and it is required for attending an audition- on campus or in Chicago.
However, we do not require students to set aside a large block of time at Chicago Unifieds, just a 10 minute audition slot. I would recommend trying to fit CCU in there if you can’t travel on campus. 
I have seen video submissions be accepted, but as our pool of auditions grows bigger and bigger by the minute, it would be very hard to accept someone off a video, especially after spending 9 hours with other students at the on campus auditions.