Please use the url to clear the cache, if you want to cache the url
https://developers.facebook.com/tools/debug/og/object/
There is an Facebook API which uses CURL to clear cache.
$url = 'https://graph.facebook.com';
$ch = curl_init();
curl_setopt( $ch, CURLOPT_URL, $url );
curl_setopt( $ch, CURLOPT_RETURNTRANSFER, true );
curl_setopt( $ch, CURLOPT_POST, true );
$params = array(
'id' => '<Website_url>',
'scrape' => true );
$data = http_build_query( $params );
curl_setopt( $ch, CURLOPT_POSTFIELDS, $data );
curl_exec( $ch );
$httpCode = curl_getinfo( $ch, CURLINFO_HTTP_CODE );
