For taxonomies please

It is possible, but you would need to modify the code to include the custom post type name. First you need to find out what the custom post type is called, then you can add it to line 62 on woocommerce-payperpost.php where it has

public static function add_custom_meta_box() {
    add_meta_box('woocommerce-payperpost-meta-box', __('WooCommerce Pay Per Post', 'textdomain'), __CLASS__ . '::output_meta_box', 'post', 'normal', 'high');
    add_meta_box('woocommerce-payperpost-meta-box', __('WooCommerce Pay Per Post', 'textdomain'), __CLASS__ . '::output_meta_box', 'page', 'normal', 'high’);
    add_meta_box('woocommerce-payperpost-meta-box', __('WooCommerce Pay Per Post', 'textdomain'), __CLASS__ . '::output_meta_box', ‘YOUR-CUSTOM-POST-TYPE-GOES-HERE', 'normal', 'high');

}

thanks, it works!

No problem!