Development Plugin in PHP for Mantis

Question

I'm developing a new plugin for my mantis:

I would like to add the field 'Organisation' when I create a User (I do it as admin). This field had been added on db in the table mantis_user_table and I have values for it.

My problem is that I can not see the new tab when I create an user and I don't know where the problem is. It's my second plugin that I develop so I m not an expert

In MantisOrganisationUser.php:

<?php
class MantisOrganisationUserPlugin extends MantisPlugin {
    function register() {
        $this->name = 'Organisation Plugin';
        $this->description = 'Adds custom organization field to user registration.';
        $this->version = '1.0';
        $this->requires = array('MantisCore' => '2.24.0');
    }

    function hooks() {
        return array(
            'EVENT_USER_CREATE' => 'addOrganizationField',
        );
    }

    function addOrganizationField($p_event, $p_user_id) {
        # Get the organization value from the form submission or another source.
        $organization_value = $_POST['organization'];  # Replace with your form field name.

        # Save the organization value to the user table.
        user_set_field($p_user_id, 'organisation', $organization_value);
    }
}

plugin_push_current("MantisOrganisationUserPlugin");

In manage_user_create_page.php:

<?php
require_once( config_get( 'path_plugins' ) . 'your_plugin_name/core.php' );
layout_page_header( lang_get( 'user_create' ) );

# Add your Organization field here
?>
<div class="container">
    <form action="<?php echo plugin_page( 'create_user' ); ?>" method="post">
        <label for="username">Username:</label>
        <input type="text" name="username" id="username" required><br>

        <label for="realname">Real Name:</label>
        <input type="text" name="realname" id="realname" required><br>

        <label for="email">E-mail:</label>
        <input type="text" name="email" id="email" required><br>

        <label for="access_level">Access Level:</label>
        <select name="access_level" id="access_level">
            <option value="25">Reporter</option>
            <option value="55">Developer</option>
            <option value="70">Manager</option>
            <!-- Add other access levels as needed -->
        </select><br>

        <label for="enabled">Enabled:</label>
        <input type="checkbox" name="enabled" id="enabled"><br>

        <label for="protected">Protected:</label>
        <input type="checkbox" name="protected" id="protected"><br>

        <!-- Custom Organization field -->
        <label for="organization">Organization:</label>
        <input type="text" name="organization" id="organization"><br>

        <input type="submit" value="Create User">
    </form>
</div>

<?php
layout_page_footer();

I want to see the new tab on create user page, but it doesn't appear.

The plugin had been installed in a correct way.