Firebase app server in php without NPM (Node.js)

I am using firebase database for my chat app and now i want to send notification to my app from my server (Without firebase console). So i want to send notification whenever firebase database triggers with related data, As i know so far(May be i am wrong.Please correct me) if i want to listen realtime database trigger i need to use firebase functions and on App server i need to install NPM commend line tool to listen firebase database trigger on app server which later made post request to FCM server for notification.

So, My issue is my server doesn't support NPM and node.js so i can't install and listen change on firebase database from app server. i during my research i came to know few php sdk which send notification but none listen change in firebase database on app server.

Is there any other way around (PHP) which can help me to listen change in firebase database and by this i can make request to FCM server for notifications.

Regards Ritu

via Ritu