Push notification won't work on ios production mode FireBase

The solution was to set gcmSandbox: false,

let push = Push.init({
  android: {
    senderID: "xxxxxxxxx"
  },
  ios: {
    senderID: "xxxxxxxxx",
    gcmSandbox: false,
    alert: "true",
    badge: false,
    sound: "true"
  },
  windows: {}
});