Multi Add is for Craft 2 only, and will not make the migration to Craft 3. Mostly because you don't need it anymore! Read about it in our blog post.
Provides an alternative controller to assist in adding multiple items to your Craft Commerce cart at once.
Also provides some handy twig tags for adding items, removing a line item, and clearing the cart directly in your templates.
Visit the Multi Add Plugin page for all documentation, guides, pricing and developer resources.
Get in touch with us via the Multi Add Support page or by creating a Github issue