wp-content/plugins/ultimate-member/includes/core/class-permalinks.php

namespace umcore;
class Permalinks { 
        function __construct() {
            add_action( 'init',  array( &$this, 'activate_account_via_email_link' ), 1 );
        }
}

I want to call this function ‘activate_account_via_email_link’ from wordpress/theme/header.php

My code so far :

$action = new umcorePermalinks;
$action->activate_account_via_email_link();

The error :
Fatal error: Uncaught Error: Class ‘umcorePermalinks’ not found in /home/xyzz/public_html/xyz/wp-content/themes/university/header-frontpage.php:5 Stack trace: #0