howto_re-create_pushnotif.ssng.rb

# Find user that has registered device (reg token registered) on server
user = User.find_by(email: '<email>')
# Find last notification object received by that user
notif = PushNotification.where(recipient_id: u.id).last
# Assign notificatable object (might be object of Post, Comment, etc) from 'notif'
obj = notif.notificatable
# Destroy last notification log, assigned as 'notif' since server won't send any duplicate notification object
notif.destroy
# Re-send notification
PushNotification.broadcast_notifications_for(obj, [user])