This is the Authorization key. You have to add it as a GET parameter.
Your auth key can be found on the [CMS](https://www.pro6pp.nl/cms).


authKey

This will give autocomplete suggestions for streets.


The address's postal code in sixpp format (1000AA)


postalCode

The address's settlement (city, town, village, or hamlet)


The amount of results returned, a number between 0 and 999.


The page to return, the variables for the next/previous pages can be found in the results Link header.
