[{"key":ISODate("2023-03-01")},{"key":ISODate("2022-03-01")}]

db.collection.aggregate([{$limit:1},{"$project":{offset:{"$range":[-90,0]}}},{$project:{_id:1,date:{"$map":{"input":"$offset","as":"o","in":{$dateTrunc:{date:{"$dateAdd":{"startDate":"$$NOW","unit":"day","amount":"$$o"}},unit:"day"}}}}}},{"$unwind":"$date"},{"$lookup":{"from":"collection","let":{"dt":"$date"},"pipeline":[{"$match":{$expr:{$eq:[{"$dateTrunc":{date:"$key",unit:"day"}},"$$dt"]}}},{"$count":"cnt"}],"as":"records"}},{$project:{_id:0,date:1,count:{$ifNull:[{$first:"$records.cnt"},0]}}}])