PushNotifications stop working after installing this plugin Community/FCM plugin

Ionic Framework
1

I am currently using ionic capacitor PushNotifications for Firebase cloud messaging. By the help of this I can get tokens.
Now I want to send notifications to all app users so I decided to use topics.

For this, I installed community/FCM plugin.

capacitor-community/fcm

I also made suggested changes in the MainActivity.java file, no error during app build.

But after installation this FCM plugin, PushNotifications(token) stop working.

Even below code starts always retuning false.

if (isPushNotificationsAvailable) {
      this.initPushNotifications();
    }

Here is my MainActivity.java file:-

package io.ionic.starter;

import com.getcapacitor.community.fcm.FCMPlugin;

import android.os.Bundle;

import com.getcapacitor.BridgeActivity;

import com.getcapacitor.Plugin;

import java.util.ArrayList;

public class MainActivity extends BridgeActivity {

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // Initializes the Bridge
    this.init(savedInstanceState, new ArrayList<Class<? extends Plugin>>() {{
      // Additional plugins you've installed go here
      // Ex: add(TotallyAwesomePlugin.class);
      add(FCMPlugin.class);
    }});
  }
}

Here my fcm.service.ts File:-

import { Component, Injectable } from '@angular/core';
import { Capacitor } from '@capacitor/core';
import { Router } from '@angular/router';
import { Storage } from '@ionic/storage';
import {
  ActionPerformed,
  PushNotificationSchema,
  PushNotifications,
  Token
} from '@capacitor/push-notifications';
// import { FCM } from '@capacitor-community/fcm';

const isPushNotificationsAvailable = Capacitor.isPluginAvailable('PushNotifications');

@Injectable({
  providedIn: 'root'
})

export class FcmService {

  public topicName = 'project';

  constructor(
    private router: Router,
    private storage: Storage
  ) { }

  initPush() {
    //This Plugin is not available on web

    if (isPushNotificationsAvailable) {
      this.initPushNotifications();
    }
  }
  // Request permission to use push notifications
  // iOS will prompt user and return if they granted permission or not
  // Android will just grant without prompting
  private initPushNotifications() {

    //console.log('Initializing HomePage');

    PushNotifications.requestPermissions().then(result => {
      if (result.receive === 'granted') {
        // Register with Apple / Google to receive push via APNS/FCM
        PushNotifications.register();
      } else {
        // Show some error
      }
    });

    PushNotifications.addListener('registration', (token: Token) => {
      alert('Push registration success, token: ' + token.value);
      //Store Devive Token in session variable
      this.storage.set("device_token", token.value);
      // FCM.getToken()
      //   .then((r) => alert(`Token ${r.token}`))
      //   .catch((err) => console.log(err));
      // now you can subscribe to a specific topic
      // FCM.subscribeTo({ topic: this.topicName })
      //   .then((r) => alert(`subscribed to topic`))
      //   .catch((err) => console.log(err));      
    });

    PushNotifications.addListener('registrationError', (error: any) => {
      //alert('Error on registration: ' + JSON.stringify(error));
    });

    PushNotifications.addListener(
      'pushNotificationReceived',
      (notification: PushNotificationSchema) => {
        //alert('Push received: ' + JSON.stringify(notification));
      },
    );

    PushNotifications.addListener(
      'pushNotificationActionPerformed',
      (notification: ActionPerformed) => {
        // alert('Push action performed: ' + JSON.stringify(notification));
        const data = notification.notification.data;
        //console.log('Action performed: ' + JSON.stringify(notification.notification));
        if (data.detailsId) {
          this.router.navigate(['/bid-project', data.detailsId]);
        }
      },
    );
  }
  //Reset all Badge count
  // resetBadgeCount() {
  //   PushNotifications.removeAllDeliveredNotifications();
  // }
  // move to fcm demo
  // subscribeTo() {
  //   PushNotifications.register()
  //     .then((_) => {
  //       FCM.subscribeTo({ topic: this.topicName })
  //         .then((r) => alert(`subscribed to topic ${this.topicName}`))
  //         .catch((err) => console.log(err));
  //     })
  //     .catch((err) => alert(JSON.stringify(err)));
  // }

  // unsubscribeFrom() {
  //   FCM.unsubscribeFrom({ topic: this.topicName })
  //     .then((r) => alert(`unsubscribed from topic ${this.topicName}`))
  //     .catch((err) => console.log(err));

  // }
}

After removing community plugin token generation started working as before.
Please tell me what wrong is with my code.