How do I download this object?

Hi Маргарита, this product here does not have any BIM/CAD files, so there is nothing to download. We have thousands of products, many of which do have files to download. You can use the format filter when you do a search and that will allow you to see only products that have the relevant files.
Alternatively, we also have a sister site called Bimsmith ( https://market.bimsmith.com ) that host great BIM content.