First off, you need to log in to Webpushify console.
Click on the Web Sites section in the navigation bar.
In the Website List page, click on the plus button to create a new web site.
In the Create Website page, it is required to enter a nickname and a domain (www.mydomain.com).
If you have multiple subdomains (site1.mydomain.com, site2.mydomain.com, etc), you have to register a website per subdomain.
You can set the rest of the fields such as notification icons and images and the widgets (confirm box and bell).
Note:Web push notification requires HTTPS to work. So, you need to set up your website to be served over HTTPS.