Get attributes in custom module

Hi !
First, thanks for your work, this module is really great.

I need to recover a specific attributes in a custom module to make some operations and add it to user profil config.

I tried to use the hook user_login to get attributes in user session. But $session->has('cas_attributes') return always false.

Someone has an idea how to get easily cas attributes in custom module ?

function MYMODULE_user_login($account){
$session = \Drupal::request()->getSession();
if ($session->has('cas_attributes')) {
$casAttributes = $session->get('cas_attributes');
}