we use spl_autoload_register function in the place of __autoload function but spl function don't return the value of creating instance name

Question

function myAutoload($class)
{
echo $class;die;
}
spl_autoload_register('myAutoload');
$obj = new clasic_card();

here the above function myAutoload have parameter has class which value is must be clasic_card but the value which is echo is (WP_Site_Health) i want to require a file when we create an instance of a class. plzz help me