Salut Nolan
Tu peux créer des champs personnaliser avec les custom type post.
Il te suffit simplement de le préciser lors de la déclaration de celui-ci dans l'élément "supports".
$args = array(
'labels' => $labels,
'public' => true,
'publicly_queryable' => true,
'show_ui' => true,
'show_in_menu' => true,
'query_var' => true,
'rewrite' => true,
'capability_type' => 'post',
'has_archive' => true,
'hierarchical' => false,
'menu_position' => null,
'supports' => array('title','editor','author','custom-fields','thumbnail','excerpt','comments'
);
Je te copie une partie de la documentation officiel de Wordpress expliquant les différents paramètres.
supports
(array) (optional) An alias for calling add_post_type_support() directly.
Default: title and editor
'title'
'editor' (content)
'author'
'thumbnail' (featured image, current theme must also support post-thumbnails)
'excerpt'
'trackbacks'
'custom-fields'
'comments' (also will see comment count balloon on edit screen)
'revisions' (will store revisions)
'page-attributes' (template and menu order, hierarchical must be true)