I’m trying to display, inside the product template page, the category the product belong to, and make it clickable with a link to the related category page.
Unfortunately, I cannot find a way to achieve that.
Product Categories are what’s called a multi-reference field for products. This means that a single product can be related to multiple categories. To display content from a multi-reference on a template page
add a collection list to the template page.
connect the list to the categories collection
add content inside the list items and bind to data coming from the categories collection
I recorded a short video of myself doing this on your site to add a button that links to the related category’s page. Hope this helps. Let me know if you have any further questions.