You can set the page design for the templates by navigating to Page Design item under the presentation folder as below.

[![enter image description here][1]][1]

Once you configure above mapping, whenever you create a page from the page template, page design will be automatically applied on the page.

You can find more details here.

https://doc.sitecore.com/xp/en/developers/93/sitecore-experience-commerce/configure-template-to-page-design-mapping.html

Hope this helps!!!


  [1]: https://i.sstatic.net/wiVNSikY.png