Dependency injection of Firebase Analytics from “@ionic-native/firebase-analytics/ngx” not working, empty object

I have imported the FirebaseAnalytics and injected to my class as below:

    import {Injectable} from '@angular/core';
    import {FirebaseAnalytics} from "@ionic-native/firebase-analytics/ngx";

        export class AnService{

          constructor(private fb:FirebaseAnalytics){}

            console.log(JSON.stringify(this.fb,null,2)); // logs empty object{}
            this.fb.logEvent('page_view', {page: "dashboard"}); 
            // returns an error: object is not a function


I have included the FirebaseAnalytics in the app.module.ts as provider.

Please help me. Standard events are collected automatically. Firebase is configured ok with my app. But I can’t implement my own events because of this problem above.