2011 Citroën Jumpy/Dispatch, Code P1445, Purge Flow Sensor

[Martin0202]

Hi there,
I have a 2011 Citroën Jumpy/Dispatch 2.0 FAP.
I get this fault message:
P1442 and P1445
It says (if I understand correctly) there is probably something wrong with the purge flow sensor.
The additive tank is filled. I checked it and was only able to add 300ml more.
Does anybody know where the sensor for the flow rate of the eolys additive is located?
And I guess the pump must be inside the Tank?