Collection exception handler

[AVTS]

Experts,

How to add the exception handler during the data import from flow(Getrpa) to collections(mago),

Below is the code i am using to collect the data from flow to local collections.

Collect(
mago,
Getrpa.Run(
LookUp(
Dusers,
email = User().Email,
route
)
)
);

Expected result. 

Error should throw if the similar record is available in the collections .

unique identifier is order number in the collections(mago).

How to achieve this