How to make iOS Push notification working


I have hard time to configure Linphone for iOS Push notification to work correctly. When the Linphone app is in the background and I call the FreePBX extension that Linphone iOS is logged to, the phone is not ringing. I’m able to make calls and receive when the app is on the foreground. I already get in touch with Linphone and they told me it that I must setup FreePBX correctly to able able to make Push Notification working.

I’d look on the present forum and I found some posts but it is not exactly what I’m looking for.

Is someone would be able to tell me how to setup Push Notification correctly on FreePBX?