Updating Colleges After Applying?

Hi! I was wondering what the best way is in order to update colleges on achievements post-applying. My update is pretty crucial to my application (I indicated I entered a competition but the results weren’t announced until this week), so should I email the schools admissions email, my regional counselor, or fax the letter to the school’s admission office? I’m getting conflicting answers so I just want the best/most efficient way. Thanks so much guys!