Background ticket.saved does no run

Hi,

I am developing an app in the background but the ticket.saved event is not detected

I have tried like this:

client.on('app.registered', function appRegistered(e) {
     client.on('ticket.saved', function(data) {
      console.log("FIRE BACKGROUND") }
)})

//and this

client.on('ticket.saved', function(data) {
      console.log("FIRE BACKGROUND") 
})