according to OneSignal's site just add this code to ask the user to allow the app to receive push notification :
window.plugins.OneSignal.registerForPushNotifications();
but it doesn't show up. And the device cannot register.
document.addEventListener("deviceready", function() {
window.plugins.OneSignal.init( "project_id",
{googleProjectNumber: "null_if_ios",
autoRegister: false},
mobile.didReceiveRemoteNotificationCallBack);
For Android, this works just fine. No need to call the registerForNotifications function.