App stops on the push init action

When I try to init the Push my app stops and the problem is on the init line:
```
const options: PushOptions = {
android: {
senderID: FCM_CONFIG.SENDER_ID
},
ios: {
alert: 'true',
badge: false,
sound: 'true'
},
windows: {}
};
const pushObject: PushObject = this.push.init(options); // app stops here
```
Just to test, if I remove that line app starts normal, with that line it stops.

I followed this link to set the push:
[Push Notifications in Ionic](https://medium.com/@ankushaggarwal/push-notifications-in-ionic-2-658461108c59)

My config.xml:
```

```