Or do you mean the cloud functions? I have the following;
Moralis.Cloud.define("getAvgGas", async function (request) {
  const query = new Moralis.Query("BscTransactions");
  const pipeline = [
    {
      group: {
        // group by "from_address"
        objectId: "$from_address",
        // add computed property avgGas
        // get average and convert wei to gwei
        avgGas: { $avg: { $divide: ["$gas_price", 1000000000]} },
      },
    },
    { sort: { avgGas: -1 } }, // sort by avgGas high to low
    { limit: 10 }, // only return top 10 results
  ];
  // the master key is required for aggregate queries
  const results = await query.aggregate(pipeline, { useMasterKey: true });
  return results;
})