Mongo jason query is failing to execute by runMangoAggregation Processor Nifi

Hi Friends,

I have mongo query which running perfectly fine from mongo shell.

b.test650.aggregate(
[
{
$group: {
"_id": {
X: "$X",
Y_DT: "$Y_DT",
Z: "$Z"
},
adj: {$sum: "$adj" },
bjc: {$sum: "$bjc" },
jbc: {$sum: "$jbc" },
mnk: {$sum: "$mnk"}
}
}
]
)

The same query when in ran from Nifi , RunMangoAggregation  throwing out error, though the mongo aggregation query changed to json type query ...

{
"$group": {
"_id": {
"X": "$X",
"Y_DT": "$Y_DT",
"Z": "$Z"
},
"adj": {"$sum": "$adj" },
"bjc": {"$sum": "$bjc" },
"jbc": {"$sum": "$jbc" },
"mnk": {"$sum": "$mnk"}
}
}

Getting following error ..

error run mongodb aggregation query.: com.fasterxml.jackson.databind.exc.MismatchedInputException:canot deserialize instace of java.util.ArayList' out of START_OBJECT token

Nifi workflow..

Processor(runMangoAggregation) configuration

What is the change I need to do in json query which supposed to executed @ runMongoAggregation  processor?