OneSignal with ionic 3

Well, how do I define a segment for a user via sdk. I have several threads already created, however, I have no idea how to define a segment for each of the users via application? NOTE: I am using the native ionic 3 plugin.

this.oneSignal.startInit('', '');
this.oneSignal.inFocusDisplaying(this.oneSignal.OSInFocusDisplayOption.Notification);
this.oneSignal.handleNotificationReceived().subscribe(data=>{
    this.onPushReceived(data.payload);
  });
this.oneSignal.handleNotificationOpened().subscribe(data =>{
        this.onPushOpened(data.notification.payload);
      })
      this.oneSignal.endInit();'