How to use proxies with PHP Curl?

First, check that you have whitelisted the proxy port in your server's firewall.

Then apply these settings in PHP cURL:

CURLOPT_TIMEOUT         => 35,
CURLOPT_CONNECTTIMEOUT  => 35,
CURLOPT_FOLLOWLOCATION  => true,
CURLOPT_MAXREDIRS       => 5,
CURLOPT_PROXY           => 'IP_HERE',
CURLOPT_PROXYPORT       => 'PORT_HERE',
CURLOPT_HTTPPROXYTUNNEL => 1,