[Solved] Air Quality: where can I find station_id

With the risk of asking a very silly question, but I have been searching for quite some time now…
For the air quality the documentation says:
stationId: Unique ID of the measuring station.

Where can I find this id? Because I know which station I would like to use but can’t find the id for this station. The configuration of the thing shows that the id is a numerical thing. Although the Air Quality site shows e.g. this: ID_BEI_DC

In the link for a station I cannot see anything that looks close to a numerical nummer to be used in the openhab item configuration

So I hope someone can help me with this one!

See:

http://aqicn.org/json-api/doc/

This information is added to the documentation.