node index.js not working like error express - node.js

Question

ok so here is what i got on cli
anyone how to fix this
i have tried
npm cache clean but its not working
node:internal/modules/cjs/loader:936
throw err;
^
Error: Cannot find module 'express'
Require stack:
- C:\Users\iftkh\Backend\index.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> (C:\Users\iftkh\Backend\index.js:1:17)
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: [ 'C:\\Users\\iftkh\\Backend\\index.js' ]

Answer 1

I think you should install express correctly, or maybe didn't required it

Answer 2

could someone solve the problem? Have similar one and can't understand it why!
everything is installed.
{
"name": "server",
"version": "1.0.0",
"description": "",
"main": "index.js",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1"
},
"author": "",
"license": "ISC",
"dependencies": {
"express": "^4.18.1",
"mysql": "^2.18.1"
}
}