app crashedエラー

nodemon app でサーバーを起動しようとすると
このようなエラーが出ます

user@fukusyun-2 graphQL % nodemon app                                          
[nodemon] 2.0.4
[nodemon] to restart at any time, enter `rs`
[nodemon] watching path(s): *.*
[nodemon] watching extensions: js,mjs,json
[nodemon] starting `node app index.js`
internal/modules/cjs/loader.js:968
  throw err;
  ^

Error: Cannot find module '/Users/user/udemy/graphQL/index.js'
    at Function.Module._resolveFilename (internal/modules/cjs/loader.js:965:15)
    at Function.Module._load (internal/modules/cjs/loader.js:841:27)
    at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:71:12)
    at internal/main/run_main_module.js:17:47 {
  code: 'MODULE_NOT_FOUND',
  requireStack: []
}
[nodemon] app crashed - waiting for file changes before starting...

初めてnodemonコマンドを使ったので
わからないことが多く、
同じようなエラーを見たのですが
解決策がわかりませんでした、、

package.json

{
  "name": "graphql",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "express": "^4.17.1",
    "mongoose": "^5.10.0",
    "nodemon": "^2.0.4"   インストール確認
  }
}

一様app.js

const express = require("express")
const graphql = require("express-graphql")
const mongoose = require("mongoose")
const app =express()

mongoose.connect('mongodb+srv://fukui:3578a@cluster0.uu61l.mongodb.net/<dbname>?retryWrites=true&w=majority')
mongoose.connection.once('open', () =>{
  console.log('db connected')
})

mongoose.use('/graphql', graphqlHTTPS)

app.use('/graphql',graphqlHTTP({
  
}))
app.listen(4000, () =>{
  console.log('listing part 4000')
})

npm fixができません

audited 604 packages in 2.12s
found 369 vulnerabilities (364 low, 2 moderate, 3 high)
  run `npm audit fix` to fix them, or `npm audit` for details
user@fukusyun-2 calender-app % npm audit fix 
npm ERR! code EAUDITNOPJSON
npm ERR! audit No package.json found: Cannot audit a project without a package.json

npm ERR! A complete log of this run can be found in:
npm ERR!     /Users/user/.npm/_logs/2020-08-25T05_33_23_586Z-debug.log
user@fukusyun-2 calender-app %

scriptの方を

"scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
     "start": "nodemon Server.js"
 }

にしてみたりといろいろいじったのですがダメでした

killall -9 node
コマンド後、でも同じく

試したコマンド
rm package-lock.json && npm i && npm audit fix
npm --prefix ./server install ./server
npm i minimatch -D
npm install npm-check-updates
npx ncu -u
npm update
npm outdated
npm audit fix
yarn add nodemon
yarn add graphql