Fiat Ducato 2021 Owner's Handbook Manual page 144

107) Fiat Professional recommends fitting
the child restraint system according to the
instructions, which must be included.
108) Never use the same lower anchorage
to attach more than one child restraint.
109) If a Universal ISOFIX child restraint
system is not fixed to all three anchorages,
it will not be able to protect the child
correctly. In a crash, the child could be
seriously or fatally injured.
142