How to add a addional field to a custom post_type

I am trying to add another field (subtitle) to my already created and existing custom post_type: team (code from functions.php in my childtheme)

<?php
/**
 * Custom Post type register framework
 */
include(get_stylesheet_directory(). '/inc/acpt/init.php');
add_action('init', 'makethem');
function makethem() {
    $args = array(
        'supports' => array( 'title', 'editor', 'page-attributes', 'thumbnail', 'excerpt'  ),
        'hierarchical' => true,
    );

    $team = new post_type('team','team', false,  $args );

}

/**
 * Initialize the metabox class
 */
add_action( 'init', 'be_initialize_team_meta_boxes', 9999 );
function be_initialize_team_meta_boxes() {
    if ( !class_exists( 'team_Meta_Box' ) ) {
        require_once( get_stylesheet_directory(). '/inc/metaboxes/fisio-metaboxes.php' );
        require_once( get_stylesheet_directory(). '/inc/metaboxes/init.php' );

    }
}
?>

And this is the code in fisio-metaboxes.php

<?php
/**
 * Include and setup custom metaboxes and fields.
 *
 * @category YourThemeOrPlugin
 * @package  Metaboxes
 * @license  https://www.opensource.org/licenses/gpl-license.php GPL v2.0 (or later)
 * @link     https://github.com/jaredatch/Custom-Metaboxes-and-Fields-for-WordPress
 */

/**
 * Define the metabox and field configurations.
 *
 * @param  array $meta_boxes
 * @return array
 */
 add_filter( 'team_Meta_Box', 'team_sample_metaboxes' );
function team_sample_metaboxes( array $meta_boxes ) {
    $prefix = '_team_';
    $meta_boxes[] = array(
            'id'         => 'team_details',
            'title'      => 'Team details',
            'post_type'      => 'team', // Post type
            'context'    => 'side',
            'priority'   => 'high',
            'show_names' => true, // Show field names on the left
            'fields'     => array(
                array(
                    'name' => 'Subtitle',
                    //'desc' => '',
                    'id' => $prefix . 'subtitle',
                    'type' => 'text'
                ),
            ),
        );
    return $meta_boxes;
}

add_action( 'init', 'team_initialize_team_meta_boxes', 9999 );
/**
 * Initialize the metabox class.
 */
function team_initialize_team_meta_boxes() {

    if ( ! class_exists( 'team_Meta_Box' ) )
        require_once get_stylesheet_directory(). '/inc/metaboxes/init.php';

}

The problem is that when in the wp-admin i whant to add a new team’s post_type post, the post_type doesn’t have the subtitle field

What am I missing?