Search on YouTube “How to add push notification in my blogger website?”
Either you will find an outdated videos or videos that will misguide you. After racking my brain on this topic I came to know that there is a file called “service worker” that should be uploaded on site’s root directory to make the push notification work.
To check whether you implementation is correct or not, you have to type in sw.js after your domain name. like yourdomain.com/sw.js
In blogger cms google doesn’t provide you the access of root directory. What other option we have? we can use Cloudflare to host that file you will get an Url of that file which you can route to yourdomain.com/sw.js with 1 million request per day allowance. And it’s free