Could you let me know the or the grade on the cover of your exercise book so I can provide the direct link?

If your book is a standalone grammar guide rather than a textbook-linked workbook:

A widely used series for German as a first foreign language. These exercise collections focus heavily on grammar and vocabulary.

Use the "Full Text" solutions to compare your sentence structure and word endings, especially for difficult topics like cases (Wem/Wen/Wessen).

Ensure the year on your book matches the online version (e.g., 2017 or newer) to avoid exercise mismatches.