Problem : Cloudflare and Whitelist IP

What can I do for WP Remote Users Sync to recognize my sites when I use cloudflare proxy for BOTH SITES ?

I found this

add_filter( ‘wprus_is_authorized_remote’, ‘wprus_is_authorized_remote_filter’, 10, 4 )
function my_ wprus_is_authorized_remote_filter(
$is_authorized_remote,
$method,
$remote_addr,
$ip_whitelist
) {
// your logic here, for example a code checking IP range, bypassing the $ip_whitelist check
if ( myfunction_ip_is_in_range( $remote_addr ) ) {
return true;
}

return $is_authorized_remote;
}

How ever I don’t know why should I do with it .

Hope you could help 🙂