mongoskin connects to Ali"s mongodb database, but the data cannot be queried when querying

connection code
var db = mongoskin.db ("mongodb://root:root_2018@dds-2zebaf8b74b085541692-pub.mongodb.rds.aliyuncs.com:3717,dds-2zebaf8b74b085542379-pub.mongodb.rds.aliyuncs.com:3717/admin?replicaSet=mgset-7977929/bobo", {safe: true});

Collection association

var collections = {
  config: db.collection("config"),
  players: db.collection("players"),
  tips: db.collection("tips"),
  tips2: db.collection("tips2"),
  records: db.collection("records"),
  users: db.collection("users"),
  ADs: db.collection("ads"),
  hardwares: db.collection("hardwares"),
  trainings: db.collection("trainings"),
  trainingStatus: db.collection("trainingStatus"),
  dayTrainings: db.collection("dayTrainings"),
  A1: db.collection("A1"),
  foreignConfig: db.collection("foreignConfig"),
  connectTestTime: db.collection("connectTestTime"),
  test: db.collection("test"),
}

data query

req.collections.test.find({}, function (error, config) {
        if (!error) {

            console.log("confsssssssssssssssssssssig", error)
        }
        console.log("testttt****", config)
    })
    console.log("****1")
    req.collections.config.findById("592fc0a37c3f2f4ac49808e9", function (error, config) {

        if (req.useragent.isAndroid) {

            for (var i = 0; i < config.toies.length; iPP) {
                config.toies[i].requiredAppVersion = "1.0";
            }
        }

query results are all null

Ali mongodb structure

user libraries cannot be accessed, but system libraries can access

what is the reason for this, guys?