Integrate Quickblox in Ionic 2

Ionic Framework ionic-v3
4

Hello plz help me,

I have added it in my app.components.ts

import * as quickblox from “quickblox”;
quickblox.init(this._utilityService.QBApp.appId, this._utilityService.QBApp.authKey, this._utilityService.QBApp.authSecret, this._utilityService.QBApp.CONFIG);

error_handler.js:60 ReferenceError: Strophe is not defined