如何在app.yaml“Google App Engine”中定义静态网址？

I am trying to make an ajax call in my project to the file in the root directory named abc.php. This ajax call gets succeed when I try it on local server. But on server it gives 500 server error.

I think the problem is that I need to set the static url in app.yaml. According to the given doc. I implemented the following code:

handlers:

- url: /abc
  script: abc.php

# Serve images as static resources.
- url: /(.+\.(gif|png|jpg|jpeg|css|js|pdf|woff|woff2|eot|svg|ttf|ico))$
  static_files: \1
  upload: .+\.(gif|png|jpg|jpeg|css|js|pdf|woff|woff2|eot|svg|ttf|ico)$
  application_readable: true

- url: /.*
  script: index.php

But I am still not able to access abc url on server. Can anyone please tell what is wrong with it?