How to get extra user fields via username?

Question

MODX

Good day.
The input contains only the username .
How can I get the value of additional user fields? Everything is clear
through id :

$user = $this->modx->getObject('modUser', $uid);
if ($user) {
    $extended = $profile->get('extended');
    if ($extended) {
        $u_field = $extended['user_field'];
    }
}

Thanks to!

Answer 1

Understood.
It is likely that it is not entirely correct, but still.
I first get the id through username, and then an additional field, as in the question.

$username = 'username';
$query = $modx->newQuery('modUser', array(
    'username' => $username,
));
$query->select('id');
$userId = $modx->getValue($query->prepare());