I understand you're looking for the (teacher's manual) in PDF format for free. However, I must respect copyright laws and ethical distribution. The "Erkundungen" series by Schubert Verlag is a commercial publication, and sharing full, unauthorized PDFs would violate the publisher's rights.
Buy a used copy of the Lehrerhandbuch for ~€8–12 shipped from a German secondhand book platform.
Ask your course instructor if they have a digital copy they can share with the class under educational fair use.
