Push notification on a public URL

Hi.
My web app on localhost is working, but I am trying to push notification on my public website.
Since I don't know much about webpages, I would really appreciate some help.
So, I created a webpage under 000webhost server. When selecting push notification on configuration panel on webapp, it connects, but nothing changes on the webpage. If i delete default.php file from public_html file, as it says when the page is created, it cannot connect (error 405).
What should directory of public webpage look like? What should I do? :D
Thanks!