how to provide subscriptions only for some users

Hi,

OneSignal seems to be a great solution for me and I succeeded to send test notifications with my wordpress blog.

But I don’t understand how to deal with your documentation https://documentation.onesignal.com/docs/wordpress to setup the plugin for my needs :

I don’t want all visitors to see your subscription button and subscribe to my notifications :

1) Is it correct I have to disable automatic initialization of OneSignal by enabling “Use my own SDK initialization script” in your plugin’s options ?

2) Then, I suppose I have to initialize OneSignal by rewriting “onesignal_initialize_sdk-filter” for my needs following your example.

3) I don’t understand your sentence “…you must them manually initialize OneSignal in JavaScript on all pages” because the following lines are PHP, not Javascript !?

<?php
add_filter('onesignal_initialize_sdk', 'onesignal_initialize_sdk_filter', 10, 1);
function onesignal_initialize_sdk_filter($onesignal_settings) {
    // Returning true allow the SDK to initialize normally on the current page
    // Returning false prevents the SDK from initializing automatically on the current page
    return true;
}

4) In which file must I paste this code ? in my functions.php inside my child theme or somewhere else ?

Thanks for your help, I’m lost.