Short TypeScript import statement syntax not working in Angular

I am trying to shorten the imports statements in my Angular project i.e

import { AuthenticationService } from '../_services/authentication.service';

to

import { AuthenticationService } from '@app/_service';

I am following an article where the author has used this technique and I did as he described but when I try to serve the application, I am get the error that module '@app/_service is not found in terminal i.e

  src/app/_helpers/jwt-interceptor.ts(6,41): error TS2307: Cannot find module '@app/_services'.

Author described to do the following changes in tsconfig.json

my tsconfig.json is as below.

{
  "compileOnSave": false,
  "compilerOptions": {
    "baseUrl": "./",
    "outDir": "./dist/out-tsc",
    "sourceMap": true,
    "declaration": false,
    "downlevelIteration": true,
    "experimentalDecorators": true,
    "module": "esnext",
    "moduleResolution": "node",
    "importHelpers": true,
    "target": "es2015",
    "typeRoots": [
      "node_modules/@types"
    ],
    "lib": [
      "es2018",
      "dom"
    ]
  },
  "paths": {
    "@app/*": ["src/app/*"],
    "@environments/*": ["src/environments/*"]
  },
  "angularCompilerOptions": {
    "fullTemplateTypeCheck": true,
    "strictInjectionParameters": true
  }
}

I have tried this solution described in this video too but no luck. I am also using index.ts file to export all modules in a directory as described in article.

Short Imports with TypeScript Path Mapping

Any solution for this problem OR what am I doing wrong here?