How to set proxy in Firefox by url?

Question

proxy

Hello. I'm trying to set up a proxy in FF by url. In the settings I enter the url: example.com/p/andrew/procy.pac
Upon request to this address, the web server generates the following response:
function FindProxyForURL(url,host) {return "111.111.111.111:1111";}
with the proxy address. But for some reason the proxy is not working. If I go to 2ip.ru, then the real IP is shown. Proksya 100% working. There is a suspicion that the matter is in the headers returned by the server. They are:

Accept-Ranges:bytes
Cache-Control:no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Connection:keep-alive
Content-Type:text/html
Date:Sat, 02 May 2015 20:36:21 GMT
ETag:bf60cfbc972fca2e6eb8f686b253ab9f
Expires:Thu, 19 Nov 1981 08:52:00 GMT
Last-Modified:Sat, 02 May 2015 20:36:21
Pragma:no-cache
Server:nginx/1.8.0
Transfer-Encoding:chunked
X-Powered-By:PHP/5.3.3

Tell me, what could be the problem? Why is the proxy not pulled into the browser?

Answer 1

foxyproxy can do this