使用ionic添加可选配置项的标准方法是什么？

{
  "apiUrl": "https://api.example.com",
  "apiKey": "your-api-key"
}

import { HttpClient } from '@angular/common/http';

constructor(private http: HttpClient) {}

getConfig() {
  return this.http.get('assets/config.json');
}

import { ConfigService } from './config.service';

constructor(private configService: ConfigService) {}

getData() {
  this.configService.getConfig().subscribe(config => {
    const apiUrl = config.apiUrl;
    const apiKey = config.apiKey;
    // 使用配置项进行相应的操作
  });
}