MODULE_NOT_FOUND: Error: Cannot find module 'fs-extra'

Question

I'm getting the following error when running npm start. I have installed fs-extra before so I don't understand why this is happening. How can I resolve this issue?

Error: Cannot find module 'fs-extra'
Require stack:
- /Users/user/Desktop/beirut-dc-main/tools/build-output.js
    at Function.Module._resolveFilename (node:internal/modules/cjs/loader:933:15)
    at Function.Module._load (node:internal/modules/cjs/loader:778:27)
    at Module.require (node:internal/modules/cjs/loader:1005:19)
    at require (node:internal/modules/cjs/helpers:102:18)
    at Object.<anonymous> (/Users/user/Desktop/beirut-dc-main/tools/build-output.js:1:13)
    at Module._compile (node:internal/modules/cjs/loader:1101:14)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1153:10)
    at Module.load (node:internal/modules/cjs/loader:981:32)
    at Function.Module._load (node:internal/modules/cjs/loader:822:12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:81:12) {
  code: 'MODULE_NOT_FOUND',
  requireStack: [
    '/Users/user/Desktop/beirut-dc-main/tools/build-output.js'
  ]
}