How to debug external js files in angular

Not sure if this is the right place to post a question (if not, let me know). I'm new to Angular and i would like to somehow debug one of the external js files in my project with "Debugger for chrome" or any other way...

tools: visual studio code v1.13.1 node v6.10.3 angular cli v10.0.6

launch.json

{
"version": "0.2.0",
"configurations": [

    {
        "type": "chrome",
        "request": "launch",
        "name": "Launch Chrome against localhost",
        "url": "http://localhost:4200/",
        "webRoot": "${workspaceRoot}",
        "sourceMaps": true
    },
    {
        "type": "chrome",
        "request": "attach",
        "name": "Attach to Chrome",
        "port": 9222,
        "sourceMaps": true,
        "webRoot": "${workspaceRoot}"
    }
]

angular-cli.json

{
  "$schema": "./node_modules/@angular/cli/lib/config/schema.json",
  "project": {
    "name": "debugging-test"
  },
  "apps": [
    {
      "root": "src",
      "outDir": "dist",
      "assets": [
        "assets",
        "favicon.ico"
      ],
      "index": "index.html",
      "main": "main.ts",
      "polyfills": "polyfills.ts",
      "test": "test.ts",
      "tsconfig": "tsconfig.app.json",
      "testTsconfig": "tsconfig.spec.json",
      "prefix": "app",
      "styles": [
        "../node_modules/bootstrap/dist/css/bootstrap.css",
        "../node_modules/icheck/skins/square/aero.css",
        "styles.css"
      ],
      "scripts": [
        "../node_modules/jquery/dist/jquery.js",
        "../node_modules/icheck/icheck.js"
      ],
      "environmentSource": "environments/environment.ts",
      "environments": {
        "dev": "environments/environment.ts",
        "prod": "environments/environment.prod.ts"
      }
    }
  ],
  "e2e": {
    "protractor": {
      "config": "./protractor.conf.js"
    }
  },
  "lint": [
    {
      "project": "src/tsconfig.app.json"
    },
    {
      "project": "src/tsconfig.spec.json"
    },
    {
      "project": "e2e/tsconfig.e2e.json"
    }
  ],
  "test": {
    "karma": {
      "config": "./karma.conf.js"
    }
  },
  "defaults": {
    "styleExt": "css",
    "component": {}
  }
}

No problems with debugging ts files, or any code that i had written.

All the code of a needed file is presented in a single string, i guess it is bundled, that's the reason why i can't debug it.

I'm placing breakpoints, but when debugger runs they become grey with message "Breakpoint ignored because generated code not found (source map problem?)"

Is there a way how i can accomplish that? (using vs code, or in chrome browser does not matter)

In case of need I will provide all additional information.

Thanks in advance!