How to use cordova plugin in a typescript cordova

I have a cordova +angular+ typescript project in which I'm trying to use the juspay-ec-sdk-plugin for Cordova. I've tried the solutions at Cordova plugin in Angular 4 Typescript application and cordova plugin cannot resolve in typescript but with no success. How can I refer to this plugin in my typescript code? PS: I've tried installing ngCordova typings but it didn't work.

I like in my main component app.component.ts control de deviceready and use a service to "store" the "cordova"

Some like

declare var cordova: any;  //<--declare "cordova"
declare var window:any;    //<--declare "window"

//An enum of events
export enum CordovaEvent {BackButton,Resume,Pause}

//In constructor inject our "CordovaService", it's only to store cordova
constructor(private cordovaService: CordovaService){}
ngAfterViewInit() {
    document.addEventListener('deviceready', this.onDeviceReady.bind(this), false);
  }
  onDeviceReady() {
    ..here I have "cordova".., we can, e.g.
    ..and I have the pluggings...

    cordova.getAppVersion.getVersionNumber().then(version => {
      ..make something with "version"
    });
    this.cordovaService.cordova=cordova //<--store "cordova" in a service
    this.cordovaService.isCordoba = true; //<--store in a variable in a service if
                                          //I'm in cordova or not

    // we can control the 'pause','resume',backbutton...
    document.addEventListener('pause', this.onPause.bind(this), false);
    document.addEventListener('resume', this.onResume.bind(this), false);
    document.addEventListener("backbutton", this.onBackKeyDown.bind(this), false);

  };

  onPause() {
    //If our service has a function sendEvent
    this.cordovaService.sendEvent(CordovaEvent.Pause);
  };

  onResume() {
    this.cordovaService.sendEvent(CordovaEvent.Resume);
  };

  onBackKeyDown(e) {
    this.cordovaEventService.sendEvent(CordovaEvent.BackButton);
    e.preventDefault();
    e.stopPropagation();

  };

//Our cordovaService

export class CordovaService {

    private listeningSource:Subject<CordovaEvent>=new Subject<CordovaEvent>();
    cordovaEvent:Observable<CordovaEvent>=this.listeningSource.asObservable();

    isCordoba:boolean=false;
    cordova:any;

    constructor() {
    }

    sendEvent(evento:CordovaEvent)
    {
        this.listeningSource.next(evento);
    }
}