我需要帮助！！！我尝试使用我的连接字符串连接到 mongodb atlas，但我无法连接。我不知道如何继续。我有一个准系统应用程序。我收到一个连接错误（一个 mongooseServerSelectionError）和一个未处理的 Promise Rejection Warning。
这是错误：
connection error: MongooseError [MongooseServerSelectionError]: connect ECONNREFUSED 127.0.0.1:27017
at new MongooseServerSelectionError (/Users/jagnoorg/Documents/personal-projects/monkey-den/project2/node_modules/mongoose/lib/error/serverSelection.js:22:11)
at NativeConnection.Connection.openUri (/Users/jagnoorg/Documents/personal-projects/monkey-den/project2/node_modules/mongoose/lib/connection.js:808:32)
at Mongoose.connect (/Users/jagnoorg/Documents/personal-projects/monkey-den/project2/node_modules/mongoose/lib/index.js:333:15)
at Object.<anonymous> (/Users/jagnoorg/Documents/personal-projects/monkey-den/project2/server/db/index.js:4:10)
at Module._compile (internal/modules/cjs/loader.js:1157:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:1177:10)
at Module.load (internal/modules/cjs/loader.js:1001:32)
at Function.Module._load (internal/modules/cjs/loader.js:900:14)
at Module.require (internal/modules/cjs/loader.js:1043:19)
at require (internal/modules/cjs/helpers.js:77:18)
at Object.<anonymous> (/Users/jagnoorg/Documents/personal-projects/monkey-den/project2/server/bin.js:33:10)
at Module._compile (internal/modules/cjs/loader.js:1157:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:1177:10)
at Module.load (internal/modules/cjs/loader.js:1001:32)
at Function.Module._load (internal/modules/cjs/loader.js:900:14)
at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:74:12) {
message: 'connect ECONNREFUSED 127.0.0.1:27017',
name: 'MongooseServerSelectionError',
reason: TopologyDescription {
type: 'Single',
setName: null, …