Oh dear.
The quick connector is part of the plastic pipe if you want a new one from fiat it will be expensive.
Otherwise remove connector from filter housing and find some fuel hose that will push over the plastic pipe and the pipe on fuel filter, clamp gently with two hose clamps.
If you can get the pipe from the filter down to the metal pipe from a breaker, just cut the plastic pipe, you can rejoin it to your van with some rubber fuel hose pushed over the plastic pipe ends.