Web Push Notifications with JS + PHP

Hello, I have little time and need to implement web push notifications. This project to create simple sample scripts, which make it easier for me to understand how this works. IMPORTOTANT: DO NOT USE 3RD-PARTY SOFTWARE OR LIBRARIES - just plain php and javascript Create a PHP script [login to view URL]: when the user opens this scripts, the javascript service worker is created and subscribes to Push Notifications Whenever the web browser queries a push notification, a sample Message ("Hello World") should be displayed. Create also all other javascript and php files required. Make it as simple as possible. The scripts should run on any lamp/xamp environment without special plugins or modules.