How to clear Facebook Sharer cache?

I found a solution to my problem. You could go to this site:

https://developers.facebook.com/tools/debug

...then put in the URL of the page you want to share, and click "debug". It will automatically extract all the info on your meta tags and also clear the cache.

Use api Is there an API to force Facebook to scrape a page again?

$furl = 'https://graph.facebook.com';

$ch = curl_init();

curl_setopt( $ch, CURLOPT_URL, $furl );
curl_setopt( $ch, CURLOPT_RETURNTRANSFER, true );
curl_setopt( $ch, CURLOPT_POST, true );
$params = array(
    'id' => '<update_url>',
    'scrape' => true );
$data = http_build_query( $params );
curl_setopt( $ch, CURLOPT_POSTFIELDS, $data );

curl_exec( $ch );
$httpCode = curl_getinfo( $ch, CURLINFO_HTTP_CODE );