Import JSON in Angular

import.ts

import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import jsonCfg from '../../../data/config.json';

@Injectable()
export class AppCfg {

    constructor(private http: HttpClient) {}

    load(): Promise<void> {
      return new Promise<void>((resolve, reject) => {
          const jsonFile = <unknown>jsonCfg;
          this.customCfg = <any>lokalumJsonFile;
          console.log(`[CFG_LOADED]`);                
          resolve();
      });     
    }