Could you teach how I use this plugin?

It’s quite simple;

1. Login as a shop manager or administrator.
2. Add products to your cart
3. Go to cart page
4. Copy the url that is displayed below the cart

That’s it! The url can be used for email campaigns for example.

If no url is displayed, please let me know what theme you are using. As an alternative, you could also do it manually:

1. Lookup the ids of the products you want to be added to the cart by the url (id is visible in WooCommerce – Products)
2. Manually create link, for example: www.my-shop.com/cart/fill_cart=1x66,2x77 Will add product 66 once to the cart, and product 77 twice.