Need OneSignal Integration with webhooks

I’m trying to make an event-based notification system with the integration of oneSignal and Ghost Cms.

What I actually want is,’ Whenever a new post is published, I want a URL to ping to Onesignal and it should send a notification to all the subscribers’

Where Can I find this URL and How do I integrate this with Ghost Using webhooks?

Unless you want to code your own middleware, receive Ghost hook event and then send notification to OneSignal using their SDK, you can possibly integrate them using Zapier as the middle layer:

Receive an event from Ghost using Post Published trigger:

Then send Push Notification with:

Is there any way to do it without zapier or third party automation tool ?