Trying to sort by category

HI, I’m trying to make a report to have list of product.
but i want to sort the products by category. How can i do it please?

As product may have many categories, I do not see how you can define an order?

i modified for products to have just one categorie

No one has an idea on how i can manage to do this?

If you have a Many2One to the category, you can just set the order on it like [('category', 'DESC')].