终端错误-有人可以向我解释我应该在哪里寻找错误吗?

我刚在终端中收到此错误-有人可以向我解释我应该在哪里查找错误吗?我不知道应该去哪里...

charl@DESKTOP-PDIRO0T MINGW64 ~/Desktop/IRONHACK/Week-9/finalproject/api (master)
$ npm start

> api@0.0.0 start C:\Users\charl\Desktop\IRONHACK\Week-9\finalproject\api      
> node ./bin/www


C:\Users\charl\Desktop\IRONHACK\Week-9\finalproject\api\node_modules\mongoose\lib\connection.js:579
    throw new MongooseError('The `uri` parameter to `openUri()` must be a ' +  
    ^
Error [MongooseError]: The `uri` parameter to `openUri()` must be a string, got "undefined". Make sure the first parameter to `mongoose.connect()` or `mongoose.createConnection()` is a string.
    at new MongooseError (C:\Users\charl\Desktop\IRONHACK\Week-9\finalproject\api\node_modules\mongoose\lib\error\mongooseError.js:10:11)
    at NativeConnection.Connection.openUri (C:\Users\charl\Desktop\IRONHACK\Week-9\finalproject\api\node_modules\mongoose\lib\connection.js:579:11)
    at Mongoose.connect (C:\Users\charl\Desktop\IRONHACK\Week-9\finalproject\api\node_modules\mongoose\lib\index.js:333:15)
    at Object.<anonymous> (C:\Users\charl\Desktop\IRONHACK\Week-9\finalproject\api\app.js:22:4)
    at Module._compile (internal/modules/cjs/loader.js:1158:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1178:10)  
    at Module.load (internal/modules/cjs/loader.js:1002:32)
    at Function.Module._load (internal/modules/cjs/loader.js:901:14)
    at Module.require (internal/modules/cjs/loader.js:1044:19)
    at require (internal/modules/cjs/helpers.js:77:18)
    at Object.<anonymous> (C:\Users\charl\Desktop\IRONHACK\Week-9\finalproject\api\bin\www:7:11)
    at Module._compile (internal/modules/cjs/loader.js:1158:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1178:10)  
    at Module.load (internal/modules/cjs/loader.js:1002:32)
    at Function.Module._load (internal/modules/cjs/loader.js:901:14)
    at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:74:12) {
  message: 'The `uri` parameter to `openUri()` must be a string, got "undefined". Make sure the first parameter to `mongoose.connect()` or `mongoose.createConnection()` is a string.',
  name: 'MongooseError'
}
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! api@0.0.0 start: `node ./bin/www`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the api@0.0.0 start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     C:\Users\charl\AppData\Roaming\npm-cache\_logs\2020-05-09T14_44_59_447Z-debug.log