如何在我的whmcs中调用我的注销钩子代码？

<?php
function logout_intercom{
    echo "<script type=\"text/javascript\"> Intercom('shutdown'); </script>";
    die();
}
add_hook('ClientLogout', 1, 'logout_intercom');
?>

In this above code was written as seprate hooks.php file, and i need to make invoke this code while client gets logout.
There fore I need a code that invoking my code into whmcs while whmcs client gets logout.