can't find the edit design button

Hello, i'm trying to edit the design of a product but on all the tutorials i found online, people have a "edit design" and "edit product" button like so : 

but all i have is this : 

how do i edit the design of my product ? 

thanks 🙂

3 hours ago, clement78 said:

i'm trying to edit the design of a product [page] but all i have is this

Looking at your screenshot, you are on Squarespace 7.0, whereas the video snapshot is from a Squarespace 7.1 site. On 7.0, you can edit the product page design in Design > Site Styles. The number of options available will depend on the template you are using, as each one differs on 7.0.