Typescript Decorators Class target prototype always empty

Question

I try to learn decorators in typescript and follow the instruction of the course till in function controller it's a function try to loop through class Plane property to get Metadata out of it from secret but it can't loop through because the target.prototype is always return empty object {}

import 'reflect-metadata'

@controller
class Plane {
    color: string = 'red'
    constructor() {
        this.color = 'red'
    }

    @get('/login')
    login(): void {
        console.log('Login Route Open')
    }
    @markFunction('XAF123FF2Sx1')
    fly(): void {
        console.log('Flying!!')
    }
}

function markFunction(secretInfo: string) {
    return function (target: Plane, key: string) {
        Reflect.defineMetadata('secret', secretInfo, target, key)
    }
}

function controller(target: typeof Plane) {
    target.prototype.fly = function (): string {
        return 'Hello Bytefer'
    }
    // This Line !!!
    console.log(target.prototype)
    for (let key in target.prototype) {
        const path = Reflect.getMetadata('secret', target.prototype, key)
        console.log(path)
    }
}

function get(path: string) {
    return function (target: Plane, key: string) {
        Reflect.defineMetadata('path', path, target, key)
    }
}

tsconfig.json

{
  "compilerOptions": {
    "target": "es2016",                                
    "experimentalDecorators": true, 
    "useDefineForClassFields": false,                  
    "emitDecoratorMetadata": true,                    
    /* Modules */
    "module": "commonjs",                               
    "esModuleInterop": true,                             
    "forceConsistentCasingInFileNames": true,          
    "strict": true,                                     
    "skipLibCheck": true                                 
  }
}

package.json

{
  "name": "features",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "reflect-metadata": "^0.1.13"
  }
}

nodejs v18.16.1 typescript v5.1.6

I want to know how can I get key in target.prototype from decorators in class