According to Section 14 of the Public Assembly Act, public open-air assemblies or processions must be registered with the competent authority at least 48 hours before they are announced, stating the subject of the assembly or procession.
The ZA1 department will accept your registration.

Please complete the application, print it out, sign it and send it by post to:

Kreispolizeibehörde Kleve
Directorate ZA/ZA 1/2
Kanalstr. 7
47533 Kleve