Your airbox must have been taken apart before and wasn't put back properly.
That piece (item 9 below) is attached to the snorkle part (item 1 below) of the airbox which in turn must slot into an induction pipe (item 10 below) that's bolted to the chassis leg and which is then fed into a foam pipe (not numbered, snail looking thing next to item label 15 below) and bolted to the back of the bumper.
Very easy error to make if you don't know what you are doing or is simply careless when installing the snorkle.
You want to order part number
11 61 7 833 646
should be about 15.90 Euro
Here's what it should look like:
