You must apply for a pre-approval of the courses you intend to take at the host institution after you have been allocated an exchange position.
If you enroll in other courses that the ones that have been pre-approved, you must apply to AU for an updated pre-approval that includes the new courses. This is to ensure that the examinations passed abroad will be inserted in your AU degree programme once you return home.
Upon return when you receive your official transcript of records from the host institution, you apply for the credit transfer via mystudies.au.dk, and the examinations passed abroad will be inserted in your degree programme at AU.