Onesignal Register Device issue

I have an Onesignal Push code which was working in ionic 2 but not working in ionic4 now. Here is the code.

import { OneSignal } from ‘@ionic-native/onesignal/ngx’;

this.onesignal.startInit(‘SOME_ID’, ‘SOME_ID’);

        this.onesignal.getIds().then((data) => {
          this.DeviceToken = data.userId;

        let push = Push.init({
              android: {
                  senderID: "MY_SENDER_ID"
              ios: {
                  alert: true,
                  badge: false,
                  gcmSandbox: true,
                  sound: true,
                  senderID: "MY_SENDER_ID"
              windows: {}
          push.on('registration', (data) => {
              console.log("device token ->", data.registrationId);
              this.DeviceToken = data.registrationId;

It shows me the error with Push.init (Error TS2552: Canont find name ‘Push’. Did you mean ‘push’?)

Can anybody please help me what changed in ionic 4?