Buy more products

Hi,
So, my carriage is formed by a product for each page.
How do I arrange the purchase of multiple products of the same type?
Currently should do the login .. 2-3 times depending on the type of product.
I attach the image to see a list of all my products (drop-down).
Thank you.

Hi,

I didn't understood what you wanted to do, can you explain it to me ?

Thank you.

So, I have created all product pages.
If a customer wants to buy two different products must log in 2 times.
The picture on the menu, you can see the list of products.
How can I fix?

Can you please give me your website address then I'll be able to see what the problem is ? .

www.qualitydnatest.eu

I still don't understand what you want to do.
I was able to add several times the products in the cart without having to login or out.

Please give clearer information on what you want.