parent

parent::__construct($name);

class User {
    public $username;

    function __construct($name) {
        $this->username = $name;
    }
}
class Admin extends User{
    public $admin_level;
    
    function __construct($name, $admin_level) {
        parent::__construct($name);
        $this->admin_level = $admin_level;
    }
}
$admin1 = new Admin('Tom', 'Manager');

echo $admin1->username;
echo "\n";
echo $admin1->admin_level;

If there is no constructor in child class, then parent class constructor will be called (when appropriate parameters are passed)