Writing web push notification small service (no UI needded)

I want to sent notifications to my web site's visitors This can be done by google Firebase service along with JavaScript code at the client side. Here are some references: [login to view URL] [login to view URL] [login to view URL] To send notification I need to send a request to google Firebase with this token. This feature supported by modern browsers (Chrome, Firefox, Opera and more). As you might figured, I know how to do so. I need you to simplify this process and give me a ready made code so I will only have to put my credentials in the config file. The project should include: 1) JavaScript code to ask the users for notification. (I have the service that gets and saves the token). 2) C# code to send requests to Firebase to send the notifications.