How to conditionally display an ACF custom textarea contents only to those users chosen from an ACF User field.

I have an ACF User field (allowed_users)that author’s can multiple select when they create a post. I also have an ACF textarea field (private) in the author’s post (author’s only have 1 post). I’m trying to conditionally display the textarea on the front end only for those users the author selected. This is what I have…

<?php
$allowed_users = get_field('allowed_users');
$custom_field_value = get_field('private');
$current_user_id = get_current_user_id();
if (in_array($current_user_id, $allowed_users)) {
    echo $custom_field_value;
} else {
    echo 'You do not have permission to view this content.';
}
?>