Grundsteuer
postitaja Frank (confidential) sees Saksamaa foorum
Ground tax (Grundsteuer) is collected by the twon council, due by regulation and no invoice is needed.
The procedure might vary by location, but where I live a statement of tax due and collection dates is sent to the property owner at the beginning of a calendar year. If you didn't receive it, you can probably ask the authority in charge for this information. Such official statements are often automatically generated documents without stamp or signature.