Collection users:

    _id: ObjectId,
    name: 'string',
    requests: [
        {
            ref: 'users',
            type: Schema.Types.ObjectId,
            default: null
        }
    ],

I need to aggregate the the same collection. So, here is demo data of user one

{
  "_id": {
    "$oid": "668372606b19b60fbe84e4b9"
  },
  "name": "user1",
  "requests": []
}

this is user two:

{
  "_id": {
    "$oid": "6687c6e1ebe711aac96de69d"
  },
  "name": "user2",
  "requests": [
    {
      "$oid": "668372606b19b60fbe84e4b9"
    }
  ]
}

I need to give id of user2 and aggregate requests array data and return name of user1(array can have more ids)

My query is:

        let requests = await User.aggregate([
            {
                $match: { _id: new mongoose.Types.ObjectId(userId)} //comes from frontend
            },
            { $lookup: {
                    from: "users",
                    let: { requests: "$requests" },
                    pipeline: [
                        { $match: { $expr: { $in: ["$_id", "$$requests"] }}},
                    ],
                    as: "requestsData"
                }
            }

        ]);

But it’s returns an empty array.