There a two dropdown menu options for "request desktop" in my Safari, in that menu. Translations might be imprecise because I use German locale.

But one is in a section called "Website actions", then there's another one in a section named "Website settings".

I didn't even notice it myself until now.

In earlier versions (before Liquid glass redesign I guess, which enlarged all dropdown paddings), the latter was called "always request Desktop site for xyz".