We do not recommend going on exchanges outside USN's partner portfolio
If you want to study abroad outside of USN's partner agreements, you must apply USN for "study leave" during the time you are away, and you have to apply for admission to the host institution on your own.
You are not entitled to pre-approval of the studies in this case. You can consult with the study supervisor and program coordinator before choosing your subject but you are not guaranteed to get them approved in your degree after your stay abroad.