how to make more tabs in tabular layout?

-- url of the page with the problem -- : localhost
-- HikaShop version -- : 3.2.0
-- Joomla version -- : 3.7.5
-- PHP version -- : 7.0
-- Browser(s) name and version -- : firefox 55.0.2 (64-bit)

Hi,

I like the tabular page layout very much. How to I create more tabs? I want the default Description, and add Specifications (of that product, basically that would be in the Description) and Details (also part of the Description) to it. I think that's possible, but I don't know how to do that.