Online parts source for Franke Little Butler Water Filtration System?
 

Any leads greatly appreciated. I need a grey plastic push fitting for
outlet side of the housing cap (1/4" green tube). Mine was leaking, I
overtightened, and broke it.

Franke Triflow Filter System on a Little Butler 2000 Series.

I've done some googling, but can't find an online parts source.
Nearby Franke dealers don't carry parts.