D:\work\nodejs\1helloword>node helloword3.js
node:internal/modules/cjs/loader:936
throw err;
^

Error: Cannot find module ‘express’
Require stack:
– D:\work\nodejs\1helloword\helloword3.js
[90m    at Function.Module._resolveFilename (node:internal/modules/cjs/loader:933:15)[39m
[90m    at Function.Module._load (node:internal/modules/cjs/loader:778:27)[39m
[90m    at Module.require (node:internal/modules/cjs/loader:1005:19)[39m
[90m    at require (node:internal/modules/cjs/helpers:102:18)[39m
at Object.<anonymous> (D:\work\nodejs\1helloword\helloword3.js:2:15)
[90m    at Module._compile (node:internal/modules/cjs/loader:1101:14)[39m
[90m    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1153:10)[39m
[90m    at Module.load (node:internal/modules/cjs/loader:981:32)[39m
[90m    at Function.Module._load (node:internal/modules/cjs/loader:822:12)[39m
[90m    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:81:12)[39m {
code: [32m’MODULE_NOT_FOUND'[39m,
requireStack: [ [32m’D:\\work\\nodejs\\1helloword\\helloword3.js'[39m ]
}

Solution:

D:\work\nodejs\1helloword>npm install express

added 50 packages in 2s