Slow query response over server and showing Network Error

I am trying to fetch 6 month of my brand transaction data from documents using Node JS as my backend. After 1 minutes its showing network error. Am using AWS as my web app host.

In postman its taking 3min to fetch data but in server its giving network error after just 1 min.
here is my code,

let brandData = await item.aggregate(
[
{
$match: {
$expr: {
$cond:{
if:brand_id,
then:{$eq: ["$brand_id", brand_id]},
else:’’
}

    }

  }
},
{
  $sort: {
    item: 1,
  }
},
{
  $project: {
    _id: 0,
    item_id: 1,
    uom_id: 1,
    item: 1,
    brand_id: 1
  }
},
{
  $lookup:
  {
    from: "t_100_uoms",
    let: {
      "uom_id": "$uom_id"
    },
    pipeline: [
      {
        $match: {
          $expr: {
            $eq: ["$$uom_id", "$uom_id"]
          }
        }
      }, {
        $project: {
          caption: 1,
        }
      }
    ], as: 'uom'
  }
},
{
  $addFields: {
    caption: { $first: "$uom.caption" }
  }
},
{
  $lookup:
  {
    from: "t_100_brands",
    let: {
      "brand_id": "$brand_id"
    },
    pipeline: [
      {
        $match: {
          $expr: {
            $eq: ["$$brand_id", "$brand_id"]
          }
        }
      }, {
        $project: {
          brand: 1,
        }
      }
    ], as: 'brand'
  }
},
{
  $addFields: {
    brand: "$brand.brand"
  }
},
{
  $lookup: {
    from: 't_900_sales',
    let: {
      "item_id": "$item_id"
    },
    pipeline: [
      { $unwind: "$invoice_details" },
      { $unwind: "$invoice_item_details" },
      {
        $match: {
          $expr: {
            $and: [
              { $eq: ["$invoice_item_details.item_id", "$$item_id"] },
              { $eq: ["$invoice_item_details.invoice_no", "$invoice_details.invoice_no"] },
              { $gte: ["$invoice_details.invoice_date", fromDate] },
              { $lte: ["$invoice_details.invoice_date", toDate] },
            ]

          }
        }
      },
      {
        $project: {
          _id: 0,
          netValue: { $sum: { $toDouble: "$invoice_item_details.net_value" } },
          qty: { $sum: { $toDouble: "$invoice_item_details.now_dispatch_qty" } },
          itemId: "$invoice_item_details.item_id",
        }
      },
      {
        $group: {
          _id: "$itemId",
          totalNetValue: { $sum: "$netValue" },
          qty: { $sum: "$qty" },
        }
      }
    ], as: "sales"
  }
},
{
  $addFields: {
    totalNetValue: {
      $round: [{ $ifNull: [{ $first: "$sales.totalNetValue" }, 0] }, 2]
    },
    qty: {
      $ifNull: [{ $first: "$sales.qty" }, 0]
    },
    brand: { $first: "$brand" },
  }
},
{
  $unset: ["sales", "uom"]
},
{
  $group: {
    _id:"$brand_id",
    brand: {$first:"$brand"},
    // caption:{$first:"$caption"},
    totalNetValue:{$sum:"$totalNetValue"} ,
    qty:{$sum:"$qty"}

  }
},

],
)