Every book user must first purchase a book code for a digital edition with LMS (BlinkLearning) at www.klett-sprachen.de. This book code must be activated in the "Contents" area of your BlinkLearning account.
In order to use the book in your class, you must have activated a book code. Should you still have problems, please check whether there are other books in your classroom for which you may not have (yet) acquired and activated a book code.