Error

root@Kali:~/Desktop/reverse-app-node# npm start

> reverse-app@0.0.0 start /root/Desktop/reverse-app-node
> node --inspect ./bin/www

Debugger listening on ws://127.0.0.1:9229/68079805-6415-4083-a07e-448a490b7967
For help see https://nodejs.org/en/docs/inspector
internal/modules/cjs/loader.js:550
    throw err;
    ^

Error: Cannot find module 'express'
    at Function.Module._resolveFilename (internal/modules/cjs/loader.js:548:15)
    at Function.Module._load (internal/modules/cjs/loader.js:475:25)
    at Module.require (internal/modules/cjs/loader.js:598:17)
    at require (internal/modules/cjs/helpers.js:11:18)
    at Object.<anonymous> (/root/Desktop/reverse-app-node/app.js:1:79)
    at Module._compile (internal/modules/cjs/loader.js:654:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:665:10)
    at Module.load (internal/modules/cjs/loader.js:566:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:506:12)
    at Function.Module._load (internal/modules/cjs/loader.js:498:3)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! reverse-app@0.0.0 start: `node --inspect ./bin/www`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the reverse-app@0.0.0 start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm WARN Local package.json exists, but node_modules missing, did you mean to install?

npm ERR! A complete log of this run can be found in:
npm ERR!     /root/.npm/_logs/2018-04-09T14_04_59_600Z-debug.log

Error "complete log"

0 info it worked if it ends with ok
1 verbose cli [ '/usr/bin/node', '/usr/bin/npm', 'start' ]
2 info using npm@5.6.0
3 info using node@v9.11.1
4 verbose run-script [ 'prestart', 'start', 'poststart' ]
5 info lifecycle reverse-app@0.0.0~prestart: reverse-app@0.0.0
6 info lifecycle reverse-app@0.0.0~start: reverse-app@0.0.0
7 verbose lifecycle reverse-app@0.0.0~start: unsafe-perm in lifecycle true
8 verbose lifecycle reverse-app@0.0.0~start: PATH: /usr/lib/node_modules/npm/node_modules/npm-lifecycle/node-gyp-bin:/root/Desktop/reverse-app-node/node_modules/.bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
9 verbose lifecycle reverse-app@0.0.0~start: CWD: /root/Desktop/reverse-app-node
10 silly lifecycle reverse-app@0.0.0~start: Args: [ '-c', 'node --inspect ./bin/www' ]
11 silly lifecycle reverse-app@0.0.0~start: Returned: code: 1  signal: null
12 info lifecycle reverse-app@0.0.0~start: Failed to exec start script
13 verbose stack Error: reverse-app@0.0.0 start: `node --inspect ./bin/www`
13 verbose stack Exit status 1
13 verbose stack     at EventEmitter.<anonymous> (/usr/lib/node_modules/npm/node_modules/npm-lifecycle/index.js:285:16)
13 verbose stack     at EventEmitter.emit (events.js:180:13)
13 verbose stack     at ChildProcess.<anonymous> (/usr/lib/node_modules/npm/node_modules/npm-lifecycle/lib/spawn.js:55:14)
13 verbose stack     at ChildProcess.emit (events.js:180:13)
13 verbose stack     at maybeClose (internal/child_process.js:936:16)
13 verbose stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:220:5)
14 verbose pkgid reverse-app@0.0.0
15 verbose cwd /root/Desktop/reverse-app-node
16 verbose Linux 4.14.0-kali3-amd64
17 verbose argv "/usr/bin/node" "/usr/bin/npm" "start"
18 verbose node v9.11.1
19 verbose npm  v5.6.0
20 error code ELIFECYCLE
21 error errno 1
22 error reverse-app@0.0.0 start: `node --inspect ./bin/www`
22 error Exit status 1
23 error Failed at the reverse-app@0.0.0 start script.
23 error This is probably not a problem with npm. There is likely additional logging output above.
24 verbose exit [ 1, true ]

So what fixed this?