Set a custom category in a custom post

Hi everybody,

I have a custom post “artist” and a taxonomy/category “artist category”, and i want to create (by development) a new post and set the category of the artist but it doesn’t work.

i have testing with this

function createNewPost( $response ){
    global $userMeta;

    $userID = $response->ID;
    $user = new WP_User( $userID );

    $role = $userMeta->getUserRole();
    //$catId = get_cat_ID("dj");

    if( $role = 'artiste' ){ // Assume you have custom role named 'artist'

        $newPost = array(
          'post_title'    => $user->nickname, // You can use user data here, for first_name: $user->first_name
          'post_content'  => $user->description,
          'post_status'   => 'pending',
          'post_author'   => $userID,
          'post_type'     => 'cpt_artists', // Assume, you have a custom post type named 'artist'
          'tax_input' => array('artist-category' => array('dj')
        ));

        $post_id = wp_insert_post( $newPost );

        wp_set_post_terms( $post_id, array( 'dj'), 'artist-category');

    }

}

But no working too.

For test i have listed all the taxonomy of wordpress and the result is :

category
post_tag
nav_menu
link_category
post_format

Why my custom taxonomy “artist-category” is not listed here ??

Thanks to all