Convert sql script to eloquent

recently I am using PHP Laravel with PostgreSQL and I don't know how to convert this sql script to eloquent.

SELECT v_extensions.extension, 
( 
    SELECT COUNT(v_xml_cdr.uuid) FROM v_xml_cdr WHERE v_xml_cdr.extension_uuid = v_extensions.extension_uuid AND start_stamp >= @startDate AND end_stamp <= @endDate
) 
FROM v_extensions ORDER BY count DESC LIMIT 1

I am trying to do something like this, but I don't know how can I write that extension_uuid from XmlCdr is equal to extension from Extension. Also these columns are not linked by foreign key on database.

$call = Extension::select('extension', function(){
        XmlCdr::where('extension_uuid', )
    })->limit(10)->get();

via Chebli Mohamed