Your return label does work, if your country is on the list you find here.
If you encounter challenges when trying to return your package using our return label, you can read about the use of the label here down below:
The label we have provided is a special return label that functions like a letter. Therefore, it doesn’t have a barcode like a standard return label. Since it works like a letter, the package won’t be registered when you hand it in at your local post office. However, they are legally required to accept your return package with our label attached, as it is prepaid, and the shipment to us is free of charge.
If the post office has any questions, you can inform them that the label is an IBRS label, and they can contact their supervisor, who can look it up in their system.
If you are returning the package from a country outside the EU, you will also need to fill out a CN22 or CN23 customs declaration form.