Hi,
Joomla has a content tag to be able to load a module in a Joomla article (and also in the product description):
docs.joomla.org/How_do_you_put_a_module_inside_an_article%3F
But it doesn't have the same for Joomla articles. Only the plugin I was talking about in my previous message allows for that as far as I know.
With HikaShop custom fields, you can use tags of the articles anywhere extension to add your Joomla article in a custom field.
You can also use a custom field of the table "WYSIWYG" to directly write your HTML in the HTML editor of the custom field, without relying on a Joomla article at all.